Next stop Rugby Park. Let's hope for an equally exciting fifth-round replay tomorrow night, when Kilmarnock host Aberdeen for the right to visit tonight's victors, St Mirren.

Join us for the build-up, live commentary and post-match reaction here on the BBC Sport website and on BBC Radio Scotland. Meanwhile, here's a reminder of what the Scottish Cup quarter-finals look like after that breathtaking tussle at Fir Park.

Friday, 28 February: Hibernian v Inverness Caledonian Thistle - live on BBC Scotland

Saturday, 29 February: Heart of Midlothian v Rangers; St Mirren v Aberdeen/Kilmarnock - live on BBC Scotland

Sunday, 1 March: St Johnstone v Celtic

If you want to relive the drama of the game at Motherwell, you can now read Jane Lewis' match report.

Motherwell manager Stephen Robinson is pleased with the manner in which his team fought back from being 4-1 down at half time but suggests they simply ran out of energy by the end of the match.

"We did ever so well to get ourselves back in after what was such a bad performance in the first half," he tells BBC Scotland.

"We looked devoid of confidence, made too many errors, we score a third own goal in three games, but I have to credit the players that came on to the pitch and the players that stayed on the pitch because they showed tremendous fight and spirit.

"They never gave up, they got back into it and continued to press. I thought we had a number of chances to win the game in one-v-one situations that we didn't take. Ultimately, when it comes down to penalties, it is a lottery and it wasn't the best quality of penalties.

"Let's be honest. They weren't good enough and I think we just ran out of steam in the end. People were dead on their feet and credit to St Mirren."

Image source, SNS

Motherwell manager Stephen Robinson has revealed that defender Jake Carroll looks to have picked up a serious injury.

He reckons the Irishman has damaged his Achilles.

Image source, SNS

St Mirren manager Jim Goodwin admits he wasn't even sure what to make of Motherwell manager Stephen Robinson's exceptionally attacking tactics.

"We spoke at half time and we knew what Stephen's approach was going to be in the second half - it's a cup competition and they had nothing to lose," he tells BBC Scotland.

"They might as well have gone gung-ho and they did. We couldn't cope with their shape and I couldn't even tell you what system they were playing in the end. It looked like a 3-5-2 at the start, but then all of a sudden they had four men up the park. We didn't cope with it."

Image source, SNS

St Mirren manager Jim Goodwin is delighted that his side have progressed to the quarter-finals but has been left with mixed emotions at the way they threw away a three-goal lead.

"Maybe a brilliant cup tie from everyone else's point of view, but from our's, for the first half I couldn't have been any happier, then in the second half Motherwell had nothing to lose and threw absolutely everything at us," he tells BBC Radio Scotland.

"They were playing four up front and I have to give great credit to Motherwell for that approach in the second half. We just could not live with it. So a slight tinge of embarrassment with the second-half performance then obvious relief is the only other emotion.

"I'm delighted we're in the quarter-finals of the Scottish Cup, but we will have some serious analysing to do after that. Because we just didn't do enough in the second half."

Image source, SNS

Steven Thompson
Former Scotland striker on BBC Sportsound

So St Mirren are through to face the winner of tomorrow's replay between Aberdeen and Kilmarnock.

They looked like they were on easy street as two Jonathan Obika goals, a Peter Harley own goal and a Sam Foley strike had them 4-1 at the break.

But a goal from Tony Watt followed by two wayward crosses from Rolando Aarons and Allan Campbell put Well on the ascendancy and dreaming of a famous comeback win.

However, the Buddies survived to force the game into a penalty shoot-out where they held their nerve better than their hosts.

Image source, SNS

Steven Thompson
Former Scotland striker on BBC Sportsound

They squandered a three-goal lead, they looked dead on their feet after being taken into extra-time, but St Mirren still prevail after a thrilling penalty shoot-out.

What a night of cup football at Fir Park. And what a mix of emotions for both sets of fans.

Image source, SNS

Jamie McGrath scores

Vaclav Hladky saves from Liam Donnelly

St Mirren's Tony Andreu blasts well over

Tony Watt spoons the ball over the bar

Cameron MacPherson's shot is saved by Mark Gillespie

Rolando Aarons sends Hladky the wrong way

Kyle McAllister scores down the middle

Liam Polworth levels for Motherwell

Jonathan Obika strokes his penalty home

Jermaine Hylton finds the crossbar - St Mirren are through!

James McFadden
Former Scotland forward on BBC Radio Scotland

Steven Thompson
Former Scotland striker on BBC Sportsound

An amazing Scottish Cup fifth-round tie is not quite finished yet.

At half-time in normal time, the tie looked done and dusted with St Mirren 4-1 ahead.

But Well roared back after the break and three rather fortunate goals levelled the game.

Kyle McAllister almost won it for St Mirren, who had been second best since half time, but now we have the penalty shoot-out.

Off the line!

Kyle McAllister looks to have won it for St Mirren, but the midfielder's chip is headed off the line.

Penalty kicks are looming...

Motherwell defender Jake Carroll is struggling.

His side have used all their substitutions, but the Irishman is hobbling off and Well are down to 10 men for the final three or so minutes.

James McFadden
Former Scotland forward on BBC Radio Scotland

Chance for St Mirren. Jonathan Obika has already scored twice, but the striker snatches at his effort, firing over the crossbar when his first effort rebounded back into his path.