Kilmarnock 1-2 Stenhousemuir
Second Division part-timers Stenhousemuir produced a major shock as they knocked out Scottish Communities League Cup holders Kilmarnock.
Brown Ferguson fired Stenny ahead after 19 minutes when Ryan O'Leary fouled John Gemmell following a cross into the box from Greg Ross.
It was Gemmell who headed the Scottish Premier League side further behind two minutes before the break.
Killie pressed forward after the break and Michael Nelson added a late reply.
But Stenhousemuir held on during four frantic minutes of stoppage time and are still unbeaten in all competitions this season.
Kilmarnock had five of their League Cup-winning team missing through injury, but manager Kenny Shiels paid Stenny plenty of respect by makinge only one change from the side that defeated Dundee United on Saturday, with Lee Johnston replacing Liam Kelly in midfield.
Former Killie defender Martyn Corrigan made two changes to the Stenny side from the weekend draw away to Stranraer, with Ferguson and Kevin McKinlay coming in for Andy Rodgers and Craig Anderson.
And it was the experienced Ferguson who put the visitors ahead as their counter-attacking formation proved dangerous from the kick-off.
The towering Gemmell provided a huge target up front and, after O'Leary held the striker's shirt, Ferguson stepped up to calmly send goalkeeper Kyle Letheren the wrong way.
Gemmell sent a speculative 30-yard half-volley over the crossbar and Bryan Hodge's left-foot shot minutes later was deflected inches wide off Michael Nelson as Stenny threatened to extend their lead.
Kilmarnock's Jude Winchester missed an open goal from six yards after Danny Racchi drilled the ball across the face of goal.
The holders paid for that miss five minutes later when Ferguson's deep corner-kick was misjudged by Letheren and the ball was headed into the empty net by Gemmell.
Shiels introduced tricky winger James Dayton at the interval and the Englishman was involved in a move that led to Rory McKenzie having his low shot held by Callum Reidford.
Racchi then sliced a volley a few inches too high from the edge of the 18-yard-box and McKenzie'sright-foot effort from 25 yards rattled the goalkeeper's left-hand post.
Stenny were camped inside their own half for long spells in the last 20 minutes and substitute William Gros rifled another 30-yard effort into the palms of Reidford.
Substitute Darren Smith curled a 25-yard shot past Kilmarnock's far post before Nelson headed home a Dayton free-kick with the game heading into injury-time.
Killie came within inches of taking the game to extra-time as the injured Reidford clutched the ball amid an almighty scramble just yards from goal seconds before the final whistle.
Kilmarnock manager Kenny Shiels: "If you look at what happened on Saturday when we were fantastic against Dundee United, we didn't get much credit and it was all about how poor they were, so I don't want to come across that way and talk about how poor we were.
"I'd rather give credit to Stenhousemuir than talk about some of the faults in our play.
"They came here and played really well, were 2-0 up at half-time and it should have been more, and they were better than us and we're disappointed with the outcome."
Stenhousemuir manager Martyn Corrigan: "That was good. It was delightful.
"We set our stall out, but ideally we want to play football in the right manner and we played some attacking stuff at times and, credit to the players, they worked tremendously hard and they got their rewards in the end.
"We didn't sit in. We played an attacking formation and you can see the boys were enjoying the game.
"We've got a right good team this season. They are comfortable on the ball.
"I think what you're seeing is that the lower divisions are getting closer to the SPL and that's something the country has not had for a wee while."