Aston Villa and Blackburn Rovers are just 90 minutes away from a place in the Carling Cup final, and a trip to Wembley.
Villa have the slenderest of leads after winning 1-0 in the first leg, at Ewood Park, but with home advantage tonight (Wednesday) they will be the favourites to reach the final.
James Milner scored the only goal of the game last week and if Blackburn are to progress then they must do something only two clubs have previously managed - coming from behind after the first leg to reach the final. Arsenal last achieved the feat 23 years ago.
Rovers last won the competition back in 2002, beating Tottenham Hotspur 2-1 at Cardiff's Millenium Stadium, so this would be their first trip to the new Wembley stadium. It would also be an opportunity for Allardyce to avenge the final defeat he suffered as Bolton Wanderers boss, back in 2004, when they lost 2-1 to Middlesbrough and he isn't fazed by the job his side have to do:
"The prize is so great and I just hope we give a good account of ourselves and it's enough. We've got to control the things we can and not make any rash decisions. We've not got to lose our cool and use the energy a semi-final brings in a positive manner.
"The first 90 minutes are only half-time. There's no need for panic just because we've lost the game 1-0. We've got another 90 minutes to put it right."
Martin O'Neill on the other hand is looking to get his hands on the trophy for a fifth time, after winning it twice as a player with Nottingham Forest and twice as Manager of Leicester City but he is not getting carried away despite the lead:
"We have got to approach the game on its own merit and try to win the game from that viewpoint.
"I don't think we could be thinking about having any other approach because it takes only a second to get a goal and, if Blackburn score early on, you are back to level anyway.
"Any advantage can be taken away in seconds. We must have a positive approach, absolutely, and forget the first leg in effect.
"I also think Blackburn would have taken great heart from the fact that decisions went their way at Ewood Park.
"They could have been in more serious trouble at half-time in that particular match. They came out very strongly in the second half as we expected and yet we had some chances ourselves.
"The game will be very tight."
HEAD TO HEAD
This will be the 162nd meeting between the two sides but this season is their first in this competition. The first game came way back in October 1888 with Villa running out 6-1 winners but in the return match, a month later, Rovers won 5-1 before also winning 8-1 in the FA Cup later the same season.
Villa narrowly lead the head to head with 68 wins compared to 59 for Blackburn, while 34 games have ended all square.
Brad Guzan is expected to return to the Aston Villa side as Martin O'Neill stands by his decision to play the American in cup competitions. Nigel Reo-Coker is likely to miss out after suffering an ankle injury in training and they will also be without Wilfred Bouma (toe), Moustapha Salifou (compassionate leave) and Curtis Davies (fitness).
El Hadj Diouf returns to the Blackburn squad after serving a three match ban, for a red card in the FA Cup meeting between the two sides, but Jason Roberts is still struggling with a knee problem.
David Dunn is likely to return after he was rested for Sunday's Premier League match with Fulham but after winning 2-0 Sam Allardyce could resist the temptation to make any changes.