One excuse may be fatigue, as the recent claims of Black Cats manager Steve Bruce - that players are being "flogged to death" with five games in 13 days over the festive period - looked to carry real weight amid the sloppy technique on display at Villa Park.
But that theory will provide zero consolation to Villa fans, who are watching a team which finished sixth last season plumb new depths.
They have now taken only five league points from last 27 available - and nearly handed Sunderland an early lead as their disgruntled crowd were still settling in their seats.
Heskey red card cost us - Houllier
Alert Steed Malbranque ran round the back of slumbering marker Carlos Cuellar but, though Bardsley's deep cross cleared the Spaniard, the Black Cats midfielder steered his back-post header wide.
Heskey then drew an early yellow card for Kieran Richardson, who brought down the heavyweight striker as he had raced away towards goal after pouncing on Anton Ferdinand's misjudgement of the bouncing ball.
As most home teams will, Villa started to press harder.
But the game soon descended into an ugly medley of high balls and heavy touches, with Nigel Reo-Coker wasting some decent counter-attacking work from his team-mates with a loose final ball.
Reo-Coker was then let down by Ashley Young's inability to bring the ball under control after he had pushed a smart pass through with the England winger lurking on the shoulder of Sunderland's defenders.
Stiliyan Petrov then made a bizarre decision to cross the ball, almost away from goal, when presented with a shooting chance in the box following Stewart Downing's intelligent pass.
Despite its paucity, a long delay in the match was unwelcome - young Sunderland midfielder David Meyler, who had not long returned after a cruciate ligament injury, was stretchered off after catching his studs in the turf.
Zenden sprinted on as his replacement, but within seconds made a glaring mistake that should have led to a Villa breakthrough.
The Dutchman hesitated as Downing robbed him of possession to knock a simple low cross along the six-yard box but Heskey could only hit the ball against his shin as it ballooned on to the bar.
Young then bamboozled Bardsley to whip over a fine cross but - unmarked - Heskey, who had pulled away into space well, headed wide.
The second half, almost immediately, was more expansive than the forgettable first.
Once again Malbranque had an early chance, but he could not keep his well-struck half-volley down under pressure from James Collins after Darren Bent had nodded across the box well.
Bent then nearly broke the deadlock after pressuring Collins into a mistake but, after robbing the Villa defender of the ball and getting his shot away with goalkeeper Brad Freidel beaten, the Welshman slid in to save the ball on the goal-line with his midriff.
Seconds later Henderson lashed wide when the ball landed at his feet after it pinged around the box at pace.
With Villa struggling for a foothold in the game, Young took it upon himself to make something happen. But his energetic run down the line ended with a shot that was from too wide an angle to cause Sunderland keeper Craig Gordon any trouble.
The hosts were then reduced to 10 men after Heskey pushed Henderson's jaw after his foul on Zenden, referee Kevin Friend deeming it to be violent conduct.
And the visitors made Houllier's side pay with a little under 10 minutes left.
Zenden's free-kick from wide on the right looked harmless as it crashed off the knees of Reo-Coker in the wall.
Injuries mar victory for Bruce
But Bardsley - a right-back - took a touch to control as the ball skidded towards him before cracking an instinctive low shot across Freidel into the corner of Villa's goal to give plucky Sunderland only their second away win of the season.
Danny Welbeck was stretchered off towards the end before Asamoah Gyan also found time to miss to an easy one-on-one with Freidel while Zenden was sent off after a second yellow card for an innocuous-looking foul on Petrov.
Zenden's first was for unsporting behaviour on the hour.
Villa did not crumble as they kept battling right to the end of five minutes added time, but they could not find the goal that would stop them falling down to 18th place in the Premier League.
90:00+5:03 Corner taken right-footed by Gabriel Agbonlahor, Header on goal by James Collins from inside the box goes harmlessly over the target.
90:00+4:43 Asamoah Gyan is ruled offside. Ashley Young takes the direct free kick.
90:00+3:52 Jordan Henderson gives away a free kick for an unfair challenge on Ciaran Clark. Stewart Downing restarts play with the free kick.
90:00+2:51 Richard Dunne is ruled offside. Craig Gordon takes the direct free kick.
90:00+1:33 Kieran Richardson fouled by Marc Albrighton, the ref awards a free kick. Craig Gordon restarts play with the free kick.
90:00+1:17 Asamoah Gyan is flagged offside by the assistant referee. Ashley Young restarts play with the free kick.
89:30 Carlos Cuellar challenges Cristian Riveros unfairly and gives away a free kick. Free kick taken by Craig Gordon.
88:29 Barry Bannan sends in a cross, Titus Bramble manages to make a clearance.
87:16 Substitution Nigel Reo-Coker goes off and Barry Bannan comes on.
87:16 Substitution Stiliyan Petrov leaves the field to be replaced by Marc Albrighton.
86:42 The ball is crossed by Ciaran Clark, Craig Gordon makes a save.
86:11 Effort on goal by Asamoah Gyan from deep inside the penalty area misses to the right of the goal.
85:44 The referee blows for offside against Darren Bent. Ashley Young restarts play with the free kick.
85:18 Unfair challenge on Stiliyan Petrov by Boudewijn Zenden results in a free kick. Brad Friedel takes the free kick.
85:18 Sent off Boudewijn Zenden sent off.
82:48 Substitution Danny Welbeck leaves the field to be replaced by Cristian Riveros.
79:38 Unfair challenge on Darren Bent by Richard Dunne results in a free kick. Boudewijn Zenden delivers the ball from the free kick right-footed from right wing,
79:38 GOAL - Phillip Bardsley:Aston Villa 0 - 1 Sunderland Phillip Bardsley finds the net. Aston Villa 0-1 Sunderland.
Correction - 79:25 Free kick awarded for an unfair challenge on Darren Bent by Richard Dunne. Boudewijn Zenden delivers the ball from the free kick right-footed from right wing,
Correction - 79:25 GOAL - Phillip Bardsley:Aston Villa 0 - 1 Sunderland Phillip Bardsley finds the net. Aston Villa 0-1 Sunderland.
78:36 Booking The referee shows Richard Dunne a yellow card.
78:02 Ahmed Elmohamady produces a cross, clearance by Carlos Cuellar.
77:46 A cross is delivered by Ahmed Elmohamady.
76:50 Shot by Asamoah Gyan from a long way out goes over the net.
76:29 The ball is swung over by Ashley Young.
75:35 Anton Ferdinand concedes a free kick for a foul on Gabriel Agbonlahor. Free kick crossed right-footed by Ashley Young, clearance by Anton Ferdinand.
70:16 Corner taken by Boudewijn Zenden, Header by Danny Welbeck from deep inside the penalty area misses to the left of the goal.
68:03 Emile Heskey fouled by Boudewijn Zenden, the ref awards a free kick. Free kick taken by Ashley Young.
68:03 Sent off The referee red cards Emile Heskey for violent conduct.
64:40 The ball is swung over by Ahmed Elmohamady, save by Brad Friedel.
62:27 Free kick awarded for a foul by Anton Ferdinand on Ashley Young. Free kick taken by Carlos Cuellar.
59:54 Boudewijn Zenden concedes a free kick for a foul on Emile Heskey. Ashley Young fires a strike on goal direct from the free kick.
59:54 Booking The referee shows Boudewijn Zenden a yellow card for unsporting behaviour.
58:05 Danny Welbeck takes a shot. Save by Brad Friedel.
57:30 Ashley Young takes a shot. Save by Craig Gordon.
56:31 Ahmed Elmohamady delivers the ball, clearance made by James Collins.
54:38 Substitution Asamoah Gyan is brought on as a substitute for Steed Malbranque.
Correction - 53:46 Steed Malbranque takes a shot. Blocked by Carlos Cuellar. Jordan Henderson takes the outswinging corner, Stiliyan Petrov makes a clearance.
53:46 Steed Malbranque takes a shot. Carlos Cuellar gets a block in. Outswinging corner taken by Jordan Henderson, Stiliyan Petrov makes a clearance.
52:39 Darren Bent takes a shot. Blocked by James Collins.
51:35 Stewart Downing takes a shot. Carlos Cuellar crosses the ball. The assistant referee flags for offside against Emile Heskey. Direct free kick taken by Craig Gordon. Anton Ferdinand manages to make a clearance.
51:02 Foul by Darren Bent on James Collins, free kick awarded. Direct free kick taken by James Collins.
49:28 Effort on goal by Steed Malbranque from inside the penalty area goes harmlessly over the bar.
48:39 Free kick awarded for a foul by Emile Heskey on Jordan Henderson. Craig Gordon takes the direct free kick.
45:01 The game restarts for the second half.
Half Time
45:00+5:08 The whistle is blown to end the first half.
45:00+4:17 Darren Bent challenges Richard Dunne unfairly and gives away a free kick. Direct free kick taken by Ashley Young.
45:00+3:18 Boudewijn Zenden delivers the ball, Emile Heskey manages to make a clearance.
45:00+2:51 Boudewijn Zenden takes the inswinging corner, clearance made by Emile Heskey.
45:00+2:22 Corner taken by Boudewijn Zenden from the right by-line to the near post, James Collins manages to make a clearance.
45:00+2:18 Ahmed Elmohamady sends in a cross.
45:00+1:51 Foul by James Collins on Danny Welbeck, free kick awarded. Boudewijn Zenden restarts play with the free kick.
45:00+1:51 Booking James Collins goes into the book.
45:00+1:13 The ball is sent over by Gabriel Agbonlahor, clearance by Anton Ferdinand.
44:18 The ball is sent over by Ashley Young, Emile Heskey has a headed effort at goal from deep inside the area missing to the right of the goal.
43:41 Kieran Richardson concedes a free kick for a foul on Ashley Young. The free kick is swung in right-footed by Ashley Young.
41:34 Emile Heskey fouled by Titus Bramble, the ref awards a free kick. Ashley Young delivers the ball from the free kick left-footed from left wing, clearance made by Phillip Bardsley.
41:34 Booking Titus Bramble goes into the book for unsporting behaviour.
39:57 Emile Heskey takes a shot.
38:20 Substitution Boudewijn Zenden joins the action as a substitute, replacing David Meyler.
34:28 The offside flag is raised against Darren Bent. James Collins restarts play with the free kick.
33:20 Danny Welbeck takes a shot. Brad Friedel makes a comfortable save.
31:58 Outswinging corner taken from the right by-line by Jordan Henderson, Brad Friedel makes a comfortable save.
31:16 Corner taken by Jordan Henderson from the right by-line to the near post, Emile Heskey manages to make a clearance.
30:43 The ball is swung over by Ciaran Clark, Phillip Bardsley makes a clearance.
30:08 A cross is delivered by Ahmed Elmohamady, Brad Friedel makes a comfortable save.
28:44 Ciaran Clark concedes a free kick for a foul on Jordan Henderson. Free kick taken by Craig Gordon.
28:44 Booking The referee books Ciaran Clark for unsporting behaviour.
25:12 Inswinging corner taken right-footed by Ashley Young from the left by-line, Unfair challenge on Craig Gordon by Gabriel Agbonlahor results in a free kick. Craig Gordon restarts play with the free kick.
21:38 Inswinging corner taken left-footed by Stewart Downing from the right by-line to the near post, clearance made by David Meyler.
20:58 Effort from the edge of the area by Kieran Richardson goes wide of the left-hand post.
11:14 Corner taken by Jordan Henderson, clearance by James Collins.
10:54 Outswinging corner taken by Jordan Henderson from the right by-line.
6:28 Ashley Young fouled by Kieran Richardson, the ref awards a free kick. Free kick crossed by Stewart Downing, Craig Gordon makes a save. Corner taken right-footed by Ashley Young, save by Craig Gordon.
Correction - 6:28 Kieran Richardson challenges Ashley Young unfairly and gives away a free kick. The free kick is delivered left-footed by Stewart Downing from right wing, save by Craig Gordon. Corner taken right-footed by Ashley Young, Gabriel Agbonlahor has a headed effort at goal from close in which goes wide right of the goal. The referee blows for offside against Gabriel Agbonlahor. Direct free kick taken by Craig Gordon. Corner taken by Jordan Henderson.
Correction - 5:34 Unfair challenge on Emile Heskey by Kieran Richardson results in a free kick. Stewart Downing shoots direct from the free kick.
5:34 Kieran Richardson concedes a free kick for a foul on Emile Heskey. Strike comes in from Stewart Downing from the free kick.
5:34 Booking Kieran Richardson receives a yellow card for unsporting behaviour.
3:50 The ball is swung over by Ciaran Clark, clearance made by Kieran Richardson.
2:15 Ashley Young gives away a free kick for an unfair challenge on David Meyler. Direct free kick taken by Anton Ferdinand.
1:33 The ball is swung over by Phillip Bardsley, Steed Malbranque has a headed effort at goal from close range which goes wide of the left-hand upright.
0:59 Ashley Young concedes a free kick for a foul on Kieran Richardson. Anton Ferdinand takes the free kick.
0:00 The match has kicked off.
Live text and data provided by The Press Association.
Bookmark with:
What are these?