Martin Keown
Former England defender on BBC One

Sheffield United just seem more determined right now. They are getting to the 50-50s.

Ian Dennis
BBC Radio 5 Live senior football reporter

The crowd here at Bramall Lane are now sensing that Sheffield United have got nothing to fear!

Southampton are on the attack but they're running into brick walls. Superb defending by Grimsby.

Tyrell Malacia gives it away twice in the corner as he tries to clear his lines but Casemiro eventually helps him out.

Marcus Rashford carries it through the middle but has to go back to Harry Maguire to reset.

Grimsby Town are 16th in League Two. They're two minutes away from one of the greatest results in their history. The Mariners are on the brink of knocking out Premier League opposition.

Pat Nevin
Former Scotland winger on BBC Radio 5 Sports Extra

We have got a real cup tie on now haven't we. It has built slowly but surely and this is what the FA Cup is all about.

The goal from West Ham has really lit the touch paper and Manchester United are really pushing on trying to find the goal. That is the only way to do it in the FA Cup.

Marcus Rashford drags a shot miles wide.The substitutions have added a bit of energy for Man Utd but West Ham are still ahead as we head into the final 20 minutes or so.

Kyle Walker-Peters cuts inside the box and curls a chance inches wide. Grimsby want the final whistle.

Cross, clearance, corner.

Fleetwood are throwing their bodies on the line, Burnley are pushing and pushing for the opener.

Clinton Morrison
Former Republic of Ireland striker on BBC Radio 5 Live

I would say the tempo has been loads better from the likes of Son and Moura. Them two are now showing they can create something.

Six minutes of additional time!

Casemiro crashes one from the edge of the box but it's straight at the keeper!

Anass Zaroury is still feeling the effects of a heavy challenge a few moments ago and he's limping off down the touchline with the physios.

Into the 90th minute. Will Grimsby hang on? Their travelling fans are going crazy. There are fish everywhere!

No doubt about it. Spurs have come out all guns blazing. Decent effort by Son Heung-min. The Premier League club have moved up a gear.

Things have totally opened up now. West Ham break down the left, Michail Antonio cuts inside and it's three-on-two but again he's denied by David de Gea from close range.

He has had two BIG chances for West Ham and that should have been 2-0.

Play is stopped as a Grimsby player is down with cramp. This has been an incredible effort by the League Two club. They are on the brink of a famous victory.

Andrew Priestley: Manchester United players stopping and not playing to the whistle in a FA Cup tie at home to West Ham United in the process of trailing 0-1. We’ve seen this before...

Michael Reid: Don't know what Diogo Dalot was doing, just completely switched off. Basic rule, play to the whistle.

Grimsby Town are five minutes plus stoppages from the quarter-finals of the FA Cup for the first time since 1939.