Full time: Cambridge United 0-0 Manchester United
21:52: Well what a result at the Abbey Stadium! The magic of the cup is still alive and we go again in a week's time at Old Trafford.
Well that brings an end to our live text, but it is just the start of our FA Cup coverage over fourth round weekend. We'll have coverage of all the games over the weekend so stay with IBTimes Uk for up to the minute coverage. Until then, goodbye.
21:49: Cambridge United of League Two hold Manchester United of the Premier League to secure a money-spinning replay at Old Trafford. Louis van Gaal only turned up at the Abbey Stadium in spirit as the U's held their own and made a mockery of the 75 places in the football pyramid between the two clubs.
Full time: Cambridge United 0-0 Manchester United
21:46: Was that the chance for United? Dunn punches away Januzaj's deflected shot as Van Persie closes in before Di Maria's volley is kept out with a fine low save. That might be that.
21:45: Three added minutes at the Abbey Stadium. All three results still possible.
21:40: Final throw of the dice sees Luke Shaw come on for Daley Blind but is it too little, too late?
21:39: So close for Cambridge. Donaldson crosses and Jones, facing his own goal, has to head behind for the Premier League side. Corner is punched away by De Gea but the pressure has relented on the hosts' goal.
21:36: Adnan Januzaj has been in an out of this game tonight but he plays a delicious ball across the face of goal where not a single United forward is stealing in in anticipation. Cambridge having spells of possession now but do they have the legs to keep United at bay?
21:31: Luke Chadwick on for Liam Hughes. What a story if he can notch the winner here. Around 13 minutes plus added time left.
21:29: Pressure is mounting on the Cambridge goal as we enter the last 15 minutes. The League Two side would be guarenteed a share of the gate receipts in the replay at Old Trafford which exceeds their current annual earnings. Can they hold on for a big pay day?
21:25: Another chance for United, who are edging closer. Di Maria plays in Van Persie and in his first involvement since coming on he lashes over the bar.
21:21: Ander Herrera and Robin van Persie coming on for Manchester United. The rain is teaming down and the wind is really disrupting the flow of this game, not helping United particularly who are seeking some rhythm in this second half.
21:16: Probably the best chance of the game comes for the away side. Carrick threads a pass through to Falcao who spins away and crashes goalwards but Dunn sticks out an arm and turns it over the bar.
21:14: Cambridge want a penalty as Valencia fells Tom Elliot from a high cross towards the back post. Plenty of man-handling but a penalty might be a stretch. Chris Foy agrees.
21:07: Harrison Dunk on for Sullay Kaikai after 53 minutes. Remember Robin van Persie is available for United tonight. On this basis, they'll need him.
21:03: Januzaj denied by Dunn at the near post amid a fast start to the second half from United. Cambridge not had a sniff of the ball yet.
20:58: Both sets of players out for the second half. It was dire first 45 minutes for United while Richard Money will want more of the same from Cambridge. No changes at the break and we're under way.
20:45: League Two Cambridge United are 45 minutes away from a money-spinning replay against Manchester United after holding the Premier League side in the first half.Josh Coulson has had the best chance of the tie with a header from two yards which landed onto of the roof of the net. Chris Dunn has been forced into a couple of saves from Angel di Maria and Daley Blind but otherwise United have looked uncertain, awkward and overawed by the occasion. The second half should make interesting viewing.
Half time: Cambridge United 0-0 Manchester United
20:42: Di Maria curls a free-kick woefully wide. Cambridge look like they will survive until the break. The much desired replay is within their grasp.
20:38: First sustained period of possession for United ends with Di Maria's shot being saved by Dunn after a deflection took the string out of the shot. Cambridge on the back foot and looking towards half time.
20:35: Falcao takes a wild swipe at the ball from a back post cross and it goes horrible wide. Not going the Colombian's way this evening. Di Maria has already had a shot from range saved, so United's high profile signings are failing to make an impression.
20:30: How are Cambridge not ahead? Josh Coulson inadvertently blocks a header on the line but as United ponder in defence, the centre-back heads over from all of two yards. Van Gaal's team all over the place at the back.
20:25: Yellow card for Marouane Fellaini for a clear pull back on Sullay Kaikai as Cambridge looked to break. Has defined a poor United display after 28 minutes. Cambridge spirited even if they are feeding off scraps a little.
20:21: Angel di Maria clears the stand with a wild shot from 25 yards. United not having it all their own way at all. Those 75 place between the two sides not looking very big.
20:19: Phil Jones with a kamikaze pass across his own goal and it almost allows Donaldson through but the ex-Newcastle United man's heavy first touch sees the chance come and go in an instant. Januzaj denied by Dunn following a weak volley at the other end.
20:16: Donaldson is again the primary threat for Cambridge and his cross from the right this time finds Tom Elliot but his flicked header glides wide of the goal.
20:14: Di Maria tries to feed Wilson and when the ball comes the way of Falcao his shot is blocked behind for a corner. Starting to come for United, who have started the game slowly.
20:09: First attack in anger from the visitors and it comes via their let-wing back for the evening Daley Blind, who after receiving the ball from Januzaj shoots towards the near post but Chris Dunn makes the save with his legs.
20:05: Chance for the League Two side to take a shock lead. Donaldson is over a free-kick over on the left and his flighted ball finds Tom Elliot, who escapes Marouane Fellaini, but heads wide.
20:04: Corner for Cambridge. High ball to the back post played by Ryan Donaldson and De Gea flaps at the cross before United clear. Uncertain start at the back.
20:00: Under way at the Abbey Stadium. Great atmosphere as you would expect.
19:56: Both sets of players out to a great reception at the Abbey Stadium. Almost ready to go in this David v Goliath cup clash. Cambridge couldn't, could they?
19:51: Louis van Gaal not giving much away in terms of how Manchester United will set up tonight, but it looks as though he will revert to a back four, a strategy that he admitted yesterday gives him a twitchy bum. United's defence has been a source of weakness this season and Cambridge are well equipped, as the second highest scorers in League Two, to expose such weaknesses.
19:44: Cambridge enjoyed two trips to Wembley last season so they and manager Richard Money are no stranger to the big occasion. The last time Manchester United played a game of equal importance? You'd have to go back to the days of Sir Alex Ferguson for that one.
19:37: So what might be expect tonight, bar the odd FA Cup cliches? Cambridge are the lowest ranked side left in the competition but don't let that fool you into thinking they might roll over tonight in the sight of English football's most successful club. The U's are unbeaten in five of their last seven games and are just six points outside the play-off places.
Manchester United meanwhile, as their team selection suggests, are taking this competition as a priority this season with no league title or European Cup to play for but despite occupying a top four spot their performances have been uncertain throughout the campaign. They bypassed Yeovil in round three but as the 4-0 thrashing by MK Dons in the League Cup should be a lesson that tonight could be a stiff task.
19:25: Cambridge are unchanged from the 4-0 win over Newport County but they do have Luke Chadwick, the former Manchester United player, on the bench.
Manchester United field a very strong team for their visit to the Abbey Stadium, with David de Gea, Angel di Maria and Radamel Falcao all starting. Captain Wayne Rooney has not travelled.
19:20: Team news
Cambridge United v Manchester United
Cambridge United: Dunn, Tait, Taylor, Coulson, Donaldson, Champion, Elliot, Hughes, Nelson, McGeehan, Kaikai
Manchester United: De Gea, Jones, Rojo, Blind, Valencia, Carrick, Fellaini, Januzaj, Di Maria, Wilson, Falcao.
19:15: The glamour of the FA Cup summed up in one fixture. League Two Cambridge United, who almost became distant memory several years ago due to financial troubles, host the second richest club in the world in Manchester United. Louis van Gaal's men travel to the Abbey Stadium for a testing cup tie as they pursue their only realistic piece of silverware this term. Cambridge's role has already in some ways been fulfilled but they will be seeking to produce one of the greatest shocks in the competition's history. It could be a night to remember.