For an hour Champions League hopefuls Villa failed to find any momentum, and could easily have trailed but for the woodwork that denied Martin Woods 10 minutes before the break.

Once O'Neill's side found top gear in the second half, they created enough chances to have run out easy winners.

But a combination of veteran goalkeeper Neil Sullivan, one month short of his 39th birthday, and profligacy in front of goal ensured the two teams will meet again at Villa Park on February 4.

"I thought it was a good game, and I was impressed with Doncaster," remarked O'Neill, whose side's seven-match winning away run finally came to an end.

"They played particularly well in the first half, had the better of it, and it took us some time to get into our stride.

"But in the second half we were more like ourselves. We had a couple of great chances, but didn't take them.

"Whilst in the course of the season it's another game, it is the FA Cup, and I'll take it. I'm delighted we're still in it.

"I wouldn't disagree that there was a bit of tiredness, but it's not something I want to be shouting from the rooftops.

"We've a bit of momentum going, we're unbeaten in a while, and now we've a big game at Portsmouth on Tuesday."

During Villa's second-half purple patch, James Milner was twice thwarted by Sullivan before he pulled off his best save moments later with a fingertip stop to deny towering centre-back Zat Knight.

Milner and Steve Sidwell then failed to capitalise on free headers before Gabriel Agbonlahor, who had found Sullivan at his best once in the first half, crashed a shot against the bar with only the former Scotland international to beat.

Villa were fortunate they were not made to pay for their wasted opportunities when Woods struck the post again three minutes from time with a delightful curling free-kick from 25 yards.

Rovers manager Sean O'Driscoll said: "We could have done without the replay. It's another game, I've a smallish squad and a couple of players out injured.

"I'm not saying we're disappointed to go to Villa Park because it will be a great experience, but we have to make sure the cup games take nothing away from the league.

"We've Sheffield United on Tuesday, and there's no point us having put in a good performance against a Premier League side here, and then don't turn up at Bramall Lane.

"It would make no sense."

O'Driscoll at least appreciated just how well his side performed, adding: "I thought we gave a good account of ourselves, although we were indebted to Neil on a couple of occasions.

"But then we were a whisker away from scoring ourselves.

"Villa are an excellent counter-attacking side, but we matched them and gave them problems, so I'm pleased with the performance and the result.

"When you are playing a side like Villa you know you are going to have to compete, but if that's all you do then you spend all afternoon chasing the ball.

"We didn't do that. We controlled parts of the game, were a threat, and although we've had problems scoring goals this season, we made them play as well as they did."

O'Driscoll will at least be relieved to know Emile Heskey will not be available as Villa missed yesterday's registration deadline.

O'Neill, though, cannot wait to work with the England striker again given their previous relationship at Leicester.

"I'm delighted Emile will be joining us on Monday," said O'Neill on the £3.5million buy from Wigan.

"I'm hoping he'll do well, although I don't want to put a lot of pressure on him - but if he doesn't then I'll kill him!

"But I know him, and I think he'll be a really great acquisition for us."