78' Greenwood has had a quiet night tonight. He hasn't managed a shot so far, and has only had one more touch than De Gea. A useful reminder that the teenage tearaway still has plenty of developing to do.
77' United win a free-kick as Long body checks Wan-Bissaka. The game is getting slightly bitty now, with some niggly fouls going in.
74' Smallbone fires in a cross from the left, and Lindelof puts it behind for a corner.
74' That looked like it might have been serious for Shaw, but after hobbling off, he comes straight back on. Williams sits back down.
72' Now there is a problem for the hosts. Shaw goes down after tweaking his ankle attempting to put a cross in. Williams is warming up.
71' A brief moment of concern for United as Stephens catches the side of Martial's head with his elbow, but he's up after a moment and fine to contine.
69' Shaw floats a cross towards the far post from deep on the left and it looks destined for Maguire's head, but it just flies over him.
68' Brilliant block from Bertrand! United look certain to score as Rashford bursts in from the left and latches onto Martial's reverse ball to the edge of the six-yard box, but Bertrand makes a crucial intervention to put the ball behind for a corner.
66' Ward-Prowse looks to cross from the right, but Matic gets a strong block in and Southampton work the ball back to defence.
63' Walker-Peters fires in a low cross through the legs of both Shaw and Maguire, but Adams doesn't gamble at the far post and it fizzes behind for a goal kick.
62' Fernandes attempts a first-time ball out to Rashford on the left, but it's hit too hard and all he can do is keep it in for Walker-Peters to carry it clear.
60' Fernandes has been involved in eight of Manchester United's last 12 goals in the Premier League, but he hasn't been at his best tonight.
58' Southampton haven't really managed to put a move together so far in the second half. After looking so good for the opening quarter of an hour, they haven't done an awful lot since.
56' Rashford finds a pocket of space to the left of centre, some 25 yards out. He unleashes a dipping low shot towards the bottom-left corner, and it just flies into the side netting.
54' Fernandes sees two corners easily cleared. His final ball hasn't been up to his own high standards so far tonight.
52' United launch a counter-attack which looks to break down as Fernandes misplaces a pass, but the move is revived and Rashford sees a shot deflected behind for a corner as he again drives in from the left.
51' Stephens is straight back on, the Saints reduced to 10 men for only a few seconds.
50' The physios are on for Stephens, who is down after going up for a header with Rashford. Stephens came down first and Rashford landed on his ankle. It looks painful, but he's able to hobble off and might be able to continue.
49' Ward-Prowse finds Redmond in acres of space on the left. Nobody closes him down and he gets to the edge of the area, but pulls a right-footed shot wide to the left of goal. He probably should have done better with that.
48' Ings mis-controls a ball in midfield, knocks it out of play and falls on his backside.
46' Bednarek takes no chances with a ball over the top for Martial, who had broken into the area. He might have been offside, but the defender put it out for a throw with a diving header.
45' We're off and running for the second half. No changes from either side at the break.
The hosts have been excellent going forward but, given their leakiness at the back, there is a feeling they may need at least another goal to win this. You wouldn't bet against them getting it, on current form.
This has been a good game so far, and one which United deserve to be leading. Southampton started brilliantly and led early on as Ings robbed Pogba on the edge of the area with Redmond crossing for Armstrong to fire home. Rashford had a neat finish ruled out for offside before he pulled his side level, slamming a shot into the bottom corner after good work from Martial. Martial turned the game on its head two minutes later, coming infield from the left and finding the top corner to notch his 50th Premier League goal.
45' + 4' HALF-TIME: MANCHESTER UNITED 2-1 SOUTHAMPTON
45' + 3' Coming towards the break, no outfield player has had fewer touches than Ings with 15. United have done a good job of keeping him quiet so far.
45' + 1' Ward-Prowse puts in another corner from the same side, and this time Pogba heads it clear.
45' + 1' Ward-Prowse fires in a corner from the right, and Martial gets his head on it to put it behind. There's going to be three minutes of added time.
42' Rashford glides into the area from the left and plays the ball inside, but Martial and Fernandes get in each other's way as neither calls for it.
40' Bednarek puts in a great challenge on Fernandes as the Portuguese attempts to spin his way into the area following a one-two.
39' Shaw's looping cross from the left is missed by two defenders and it comes to Wan-Bissaka, but he can't control it and the chance goes begging.
38' The action has died down a little in the last 10 minutes. Since that Pogba shot just after the drinks break, it's been more attritional stuff in midfield. Solskjaer will be keen for his side to get another goal and some daylight before the break.
36' The home side look to spring another counter-attack down the right, but the pass for Greenwood is overhit and Bertrand recovers.
34' Southampton take the ball forward again but United are snapping into tackles more than in the opening period, when they struggled to get a foot on the ball. The Saints aren't getting as much time to play it around now.
32' Southampton hold onto the ball in the United half for the first time in a little while, but all it results in is a United counter as Rashford races down the left. The ball eventually comes to Martial, and he lifts a shot some distance over the bar from the edge of the area.
30' A third of the way into the game, and it's been a great watch so far. Both teams going for it and both sets of forwards looking sharp. What more could you want on a Monday night?
28' United are still going for it since the drinks break. A neat flick from Fernandes finds Pogba in space at the edge of the area, and he goes for goal. He hits a powerful shot towards the bottom-left corner with his laces, but it's close enough to McCarthy for the keeper to beat it clear with relative ease.
27' A win tonight would, of course, take United up to third. Chelsea drop to fourth, and Leicester into fifth - which won't be good enough for the Champions League.
26' Martial has now scored 10 goals in his last nine games at Old Trafford, and that's his 50th in the Premier League for United.
25' And we'll have the drinks break. United hadn't really been in the game until Armstrong scored, but they have been in the ascendancy for the last 10 minutes or so. Two quick chances, and two well-taken goals for the hosts - that's what they're all about at the minute.
19' Fernandes gets the chance to swing the ball in from a free-kick on the right, but his cross doesn't beat the first man. The ball comes back out to him on the right and he tries again, but it meets the same result.
18' Scotland international Armstrong has been involved in five goals in his last six Premier League games, with two goals and three assists. That's as many has he managed in his previous 40 appearances.
17' NO GOAL! Rashford has the ball in the net, but the flag goes straight up! Shaw makes a good burst from left-back and fires in an excellent low ball from deep. Rashford side-foots it home first time, but he's clearly offside.
15' Southampton's pressing has been absolutely exemplary so far tonight, and it's got them the opening goal. They look good when they get the ball, too. They could be in for an exciting campaign next season if they play their cards right over the summer.
14' Southampton have lost more matches (26) and conceded more goals (82) versus Manchester United than they have against any other side in Premier League history. Time to make amends?
11' Armstrong hits a low, left-footed shot from the edge of the penalty area, straight at De Gea.
10' Great save by McCarthy, but Martial should score! Ward-Prowse gives the ball away with a loose touch at the back - think Gerrard and Ba without the slip. Martial races through, clear on goal, but McCarthy rushes out to block his shot with a strong outstretched hand.
9' Bournemouth are looking good on the ball so far, they're playing it around with confidence. United's leaky defence could be in for a test here.
7' Ings chases a loose ball down the left and finds Bertrand on the underlap. He fires a powerful low cross into the area, but it's too close to De Gea and the keeper makes an easy low catch.
6' Manchester United are unbeaten in their last 17 matches in all competitions (W13 D4) – they last had a longer such run in March 2013 under Sir Alex Ferguson, with a run of 18 matches.
5' Good early signs here that this will be an entertaining affair. Southampton don't look afraid to put numbers forward and with the goal threat of both teams, we could be in for a high-scoring game.
3' Romeu looks to find Walker-Peters with a raking ball out to the right side of the penalty area, but it's fractionally overhit and the full-back can't quite wrap his foot around the ball to cross it first time.
2' Pogba finds Fernandes with a lovely ball down the right, but Stephens just gets across in time to block his cross and prevent an early chance for Martial in the box.
1' We're off! Southampton get the ball rolling, going back to defence and lumping it forward down the left.
The teams are on their way out onto the pitch and we're almost ready for kick-off. Who are you backing?
Old Trafford is becoming a fortress again. United have lost just one of their last 15 home games (W9 D5), winning the last four in a row by an aggregate score of 13-2. However, they have only won two of their last six at home against Southampton.
Solskjaer names an unchanged side from the one which won 3-0 at Aston Villa last week, with De Gea making his 400th United appearance. Southampton field the same XI which drew at Everton. Consistency is key.
SUBS: William Smallbone, Shane Long, Pierre-Emile Hojbjerg, Jake Vokins, Angus Gunn, Will Ferry, Michael Obafemi, Jannik Vestergaard, Kevin Danso.
SOUTHAMPTON (4-4-2): Alex McCarthy; Ryan Bertrand, Jan Bednarek, Jack Stephens, Kyle Walker-Peters; Nathan Redmond, Oriol Romeu, James Ward-Prowse, Stuart Armstrong; Che Adams, Danny Ings.
SUBS: Brandon Williams, Eric Bailly, Scott McTominay, Daniel James, Sergio Romero, Juan Mata, Odion Ighalo, Andreas Pereira, Fred.
MANCHESTER UNITED (4-2-3-1): David de Gea; Luke Shaw, Harry Maguire, Victor Lindelof, Aaron Wan-Bissaka; Nemanja Matic, Paul Pogba; Marcus Rashford, Bruno Fernandes, Mason Greenwood; Anthony Martial.
After Chelsea and Leicester were both thrashed at the weekend, United can leapfrog both into third place with a win tonight. Southampton are 12th, and need a win to move ahead of Everton above them.
Hello and welcome to our live coverage of this Monday night Premier League clash, as Ole Gunnar Solskjaer’s Manchester United host Ralph Hasenhuttl’s Southampton at Old Trafford.