The newly promoted Coca-Cola Championship side gave their top-flight visitors a scare when Robert Earnshaw broke the deadlock on the hour mark but Phil Bardsley sent the match into extra-time when he levelled from close range.

- Have your say in the sport forum
- LISTEN to our latest Sports View podcast.
- Sign up for free SAFC email updates

The Black Cats went on to book their place in Saturday's draw when new boy David Healy reacted first to Andy Reid's parried effort to slot home his first goal for the club and seal a 2-1 victory.

Keane said: "If we had not won tonight then I would have said it was our own fault.

"I thought it was a cracking cup tie but I didn't think our football was that great.

The Black Cats created chances on the break before half-time with Djibril Cisse hitting the post before Dean Whitehead failed to beat Paul Smith when he ran through one-on-one.

Keane admitted: "We had decent chances in the first half but we didn't take them."

Forest came close to taking the game to penalties when Luke Chambers headed against the bar and Keane added: "Our back four deserve a lot of credit for hanging in there in extra time.

"I thought our general play was generally poor but I thought Forest were fantastic so they deserve credit."

His opposite number Colin Calderwood was satisfied with his side's efforts but conceded they were punished by their inability to see out the 90 minutes.

"I'm pleased we have performed half decently on TV and given a decent account of ourselves, so that's quite pleasing and quite a positive sign about the way we played, and our appetite was excellent," he said.

"We got about them but just that period before the end (cost us), and the boys are really disappointed they haven't seen it out.

"I thought it (the second goal) might just have been offside. But we'll get the evidence first.

"We just ran out of that effectiveness and energy to be decisive and really hurt them."

Calderwood felt that his side lifted their game for the cup tie and expects them to maintain that level of performance in the Championship as they look to build on last season's promotion.

He added: "Everyone will raise their game and we've seen that through the cup ties, and it's about that level of performance.

"That is now our expectation and there is no game that is unappetising to us this season, so there should be no lethargic displays this season because with players returning we'll be stronger and more effective."