French striker Martial finished a classic flowing move by the Red Devils that ended with Spanish midfielder Ander Herrera getting to the byline and just managing to slide in a cross into the box in the 83rd minute.
Hammers goalkeeper Darren Rudolph could just watch as the ball floated above his head to the far-post, and Martial smartly moved into the six-yard box and got the necessary touch in between the West Ham defenders for a fine strike.
It was a vital response to an astonishing free kick 15 minutes earlier by another Frenchman, West Ham’s ace playmaker Dimitri Payet. He was brought down by Dutch defender Daley Blind all of 28 yards out, and it was an unlikely attempt at beating one of the best goalkeepers in the business, United’s David de Gea.
But Payet launched the ball high over the Red Devils’ wall and it curled beautifully beyond outstretched De Gea into the left-hand corner of the net.
Up until Payet’s strike, it was a largely uninspiring quarter-final affair, with both sides unable to take advantage of several goal-scoring chances.
There was late drama as first United worked their way close to West Ham’s box, but Memphis Dupuy failed to fire a shot, and instead squared it for Marcos Rojo, whose tame effort sailed high over the crossbar.
In the first of three stoppage-time minutes, Michail Antonio drilled a 25-yard “grass-cutter” that looked to be going in, but De Gea was down to his right in time for a good parry for a corner.
Under-fire United manager Louis van Gaal – who would still be reeling from the 2-0 hammering at the hands of Liverpool in the Europa League on Thursday – would’ve left Old Trafford a relieved man, knowing that his time are still in with a chance of grabbing some silverware if they can get past West Ham in an Upton Park replay.
His Arsenal counterpart Arsene Wenger won’t be as fortunate after Watford produced a shock 2-1 FA Cup quarter-final win at Emirates Stadium in London on Sunday.
In the two other quarter-finals, Everton dispatched Chelsea 2-0 at Goodison Park on Saturday, while Crystal Palace overcame Reading by the same score away from home on Friday.
So, Watford, Everton and Crystal Palace will await one of Manchester United and West Ham in the semi-finals, with the last-four draw set to take place on Monday evening.
FA Cup Quarter-Final Results
Manchester United 1 (Anthony Martial 83’) West Ham 1 (Dimitri Payet 68’), Arsenal 1 (Danny Welbeck 88’) Watford 2 (Odion Ighalo 50’, Adlene Guedioura 63’), Everton 2 (Romelu Lukaku 77’ 82’) Chelsea 0, Reading 0 Crystal Palace 2 (Yohan Cabaye 86’ pen, Fraizer Campbell 94’).
Original source: Martial secures FA Cup replay for United