Battling Gillingham piled on the agony for Leeds boss Terry Venables as Mamady Sidibe's late strike forced a fourth-round replay.

Leeds had looked to be on their way to a straightforward victory following Alan Smith's superb free-kick on 49 minutes.

But a rush of blood from Mark Viduka 10 minutes from time handed the home side a chance of a late fightback.

Viduka was sent off for a deliberate elbow on Gills player boss Andy Hessenthaler and the home side were level within two minutes through Sidibe.

Priestfield match facts

49 mins: Smith fires home superb free-kick 80 mins: Viduka sent off for elbow on Hessenthaler 82 mins: Sidibe volleys fine equaliser

Gillingham, who reached round five last season before losing to Arsenal, had started confidently against a side with a wobbly recent record in the FA Cup.

Leeds had failed to move beyond round three in the previous two seasons and have been knocked out by lower league opposition in three of the last six campaigns.

Cardiff, Wolves and a Portsmouth side with Terry Venables as director of football have all dumped Leeds out in recent seasons.

And Hessenthaler was clearly confident of adding Gillingham's name to that list.

We are relieved to still be in the competition Leeds' Harry Kewell

The manager himself sent in an early shot that deflected wide off one of his own players, while Paul Smith drilled a long-range effort inches over.

Leeds' only threat came from lame penalty appeals after Eirik Bakke had tumbled under an innocuous challenge from Barry Ashby.

Gillingham, on the other hand, looked fresh following a break in La Manga and the beach training was probably paying off on a heavily sanded Priestfield pitch.

The home side were confidently hustling and harrying their Premiership rivals and should have made their first-half posession count with a goal on the stroke of half-time.

Nicky Southall tugs back Leeds' Harry Kewell

Hessenthaler's injury-time corner was flicked into the path of Guy Ipoua, but the big striker could only drill his volley against a post with Gary Kelly protecting his goal-line.

Reprieved, Leeds kicked off the second half with fresh hope and were quickly rewarded for upping the tempo of the game.

Paul Shaw was adjudged to have fouled Smith five yards outside the box and the England striker exacted his own punishment, curling a delightful free-kick over the wall and out of the reach of Gills keeper Wayne Brown.

This team never knows when to give up Gillingham defender Barry Ashby

Harry Kewell should have put the tie well out of the home side's reach when he outpaced Ashby to reach a bouncing ball, only to sky his shot high over Brown's crossbar.

Kewell lived to regret that miss when Sidibe superbly volleyed home two minutes from time, swivelling to crack a left-foot shot beyond Paul Robinson from Paul Shaw's cross.

Gillingham: Brown, Southall, Edge, Ashby, Hope, Hessenthaler, Smith, Saunders, Shaw, Ipoua (Wallace 72), Sidibe.
Subs not used: Bartram, Leon Johnson, Spiller, Perpetuini.

Leeds: Robinson, Kelly, Lucic, Radebe, Matteo, Bakke, Okon, Wilcox, Kewell, Smith, Viduka.
Subs not used: Martyn, Harte, Duberry, Fowler, Milner.

Sent off: Viduka (81).

Booked: Matteo.

Attendance: 11,093

Referee: N Barry (N Lincolnshire).