Nottingham Forest crashed out of the EFL Cup in a 3-2 defeat away to Swansea City, with Ange Postecoglou demanding his players "must improve". 

Forest, who parted ways with Nuno Espirito Santo earlier this month, are yet to win under their new boss, having succumbed to a 3-0 defeat away at Arsenal last Saturday. 

The Tricky Trees took a two-goal lead in the first half against the Championship side through an Igor Jesus double, but Alan Sheehan's team mounted a dramatic second-half comeback to stun the visitors. 

Having pulled one back in the 68th minute, Swansea captain Cameron Burgess netted the winner deep in stoppage time after Zan Vipotnik had restored parity.

Before Wednesday’s loss, Forest had advanced in 13 of their previous 15 EFL Cup matches against lower-division opposition, winning their last four in succession since a 2-3 defeat to Burton Albion in the 2018-19 fourth round.

A frustrated Postecoglou, who previously bullishly claimed he would have his new team fully up to speed with his methods in a matter of days, did not hide his frustration.

He told Sky Sports: "I just thought it was a game we really should have killed off long before it got to the stage that it did. 

"I got the sense we were getting a bit comfortable and thought the game would finish off easily but that's not what happens, particularly in cup football. I thought we scored a good third goal.

"I think the lads got a bit comfortable in that moment and you've got to know the warning signs.

"We had to finish them off and we had plenty of opportunities to do that, and a couple of decisions didn't go our way.

"Players just thought it would naturally finish that way and we've paid a heavy price for that. We need to improve."

Forest had 17 shots and accumulated 2.83 expected goals to Swansea's 0.72, but they must now lick their wounds ahead of a trip to Burnley in the Premier League.