East Fife produced the biggest shock of the Scottish League Cup so far by dumping out Aberdeen, while Hibernian knocked out Motherwell in a penalty shoot-out at Fir Park.
At Pittodrie, Scottish Premier League side Aberdeen fell foul to Second Division outfit East Fife, who edged a penalty shoot-out 4-3 after an epic 3-3 draw following 120 minutes of play.
Rory Fallon denied the lower league side a win in normal time with a late equaliser for the Dons, but it was the visitors who prevailed in the end, to Aberdeen's embarrassment.
Penalties were also required to settle the contest at Fir Park, where Motherwell were held to a 2-2 draw with Hibs after extra-time before the home side lost the shoot-out 7-6.
At Rugby Park, Kilmarnock were too powerful for First Division side Queen of the South, running out 5-0 winners with the help of a Paul Heffernan hat-trick. The visitors were not helped by the dismissal of Kevin Smith on 36 minutes.
Meanwhile, Second Division outfit Airdrie United posed no problems for Dundee United in a 2-0 away win for the top flight side, with Ryan Dow and Jon Daly on target.
St Mirren came out on top of an all Scottish Premier battle at McDiarmid Park, beating St Johnstone 2-0 with two goals in the first-half after Jamie Adams put through his own net and Jim Goodwin doubled their advantage on the stroke of half-time.