Toffees boss David Moyes left the Australia international on the bench as one of six changes to his starting line-up in their Carling Cup fourth-round clash.

But he was forced to call on the midfielder as League One Luton - the lowest-placed side left in the competition - held out for extra-time.

And Cahill, who only made his first appearance of the season last week after a foot injury, struck in the 101st minute as Everton made the last eight of a cup competition for the first time under Moyes.

Fellow substitute Thomas Gravesen's corner flicked the head of Town defender Jaroslaw Fojut to the far post where Cahill was lurking to prod the ball past the helpless Dean Brill.

"We kept on going at the end but it just wouldn't go in," said Blackwell.

"Going behind to a Premier League team did not affect them at all, they just kept on going. It was a fantastic performance from start to finish and it's credit to the players.

"You couldn't tell who had the money and who didn't. It wasn't Premier League against League One, it was 11 versus 11.

"David has had to throw his big guns on because I think he thought it was slipping away, and Cahill has popped up and won it for him."

Luton, League Cup winners in 1988 - the same year Everton last reached the quarter-finals - will feel hard done by after dominating the first half and frustrating their illustrious visitors throughout the second.

Phil Jagielka, Victor Anichebe and Joleon Lescott all went close for Everton in the second half, but Luton held out for extra-time.

And they even went close to forcing penalties after Cahill struck, Lescott clearing Matthew Spring's goalbound shot on the line and Stefan Wessels bravely diving at the feet of Calvin Andrew at the death.

"In the first half we were disappointed. We didn't play well, we didn't pass the ball well," said Toffees assistant Alan Irvine.

"But in the second half we created chances and should really have finished the game off.

"It's all about the result - you'll take any result to get into the quarter-finals and we'll take any result in the next round as well.

"But it was no surprise how well Luton played, we knew it would be a tough game. Luton have a very good home record and we knew it was going to be a difficult place to come."