Andy King scored an extra-time winner as Leicester City edged to a 2-1 victory over West Ham United to book their place in the fourth round of the League Cup.
The Foxes took the lead in the sixth minute when Joe Dodoo latched onto a loose ball inside the box and fired a strike past Adrian.
They came close to scoring a second moments later as Marc Albrighton's free kick was headed off the line by Andy Carroll.
However, the visitors equalised in the 26th minute when Mauro Zarate crashed a strike into the bottom corner from the edge of the box.
On the stroke of half time, Dodoo almost restored the home side's lead after being found by Albrighton, but he could only hammer his strike into the side-netting.
Another delivery from Albrighton caused panic inside the visitor's box at the start of the second half, with Carroll almost turning the ball into his own net.
The winger was becoming an increasing danger for the visitors and moments later he came close with a low strike that was kept out by the legs of Adrian.
Leicester kept up the pressure and Leonardo Ulloa threatened with a header after meeting King's cross, but again the keeper saved the attempt.
Adrian was called into action once more when he was forced to tip a long-range free kick from Christian Fuchs around the post.
Dimitri Payet and King both fired over the bar in the closing stages, as the game headed into an additional 30 minutes.
There was a real moment of controversy in the 10th minute of extra time as Mark Noble went down inside the box under a challenge from Danny Simpson.
The referee instead chose to book the West Ham captain for simulation, and his team almost fell behind a minute later as Jeffrey Schlupp broke clear of the defence and saw his low drive saved by Adrian.
Schlupp then saw another fierce attempt blocked inside the six-yard box, before James Collins forced Mark Schwarzer to tip over his header at the back post.
The game was being played at a frenetic pace and Leicester wasted another opportunity to find the net when Riyad Mahrez was played through on goal, before placing his attempt straight at Adrian.
Adrian was proving hard to beat and the keeper pulled off another important save to deny Schlupp's low drive through a crowded box.
However, with just four minutes remaining until a penalty shootout, King rose highest inside the box to direct a cross from Fuchs into the far corner to win the game for Leicester and maintain their impressive start to the season.
