It was a stunning late twist to a breathless semi-final in front of a packed Wembley Stadium, where United had led through Marouane Fellaini’s first-half strike, only for a Chris Smalling own goal to throw the momentum back in Everton’s favour after Romelu Lukaku had missed a penalty.
Everton 1-2 Man Utd
The Emirates FA Cup
Wembley Stadium connected by EE
Saturday 23 April 2016
But Martial, lively throughout, showed remarkable calm when put through on goal by substitute Ander Herrera, and sent Louis van Gaal’s side into next month’s Final.
United had lost their previous two semi-finals, including one to Everton in 2011, while the Toffees sported a proud record of having progressed from six of their previous seven.
Van Gaal had kept faith with his rising stars, with Martial, Tim Fosu-Mensah and Marcus Rashford starting, and seasoned campaigners Juan Mata and Morgan Schneiderlin on the bench.
Perhaps the intention was to run at a patched-up Everton defence, where Muhamed Besic was pressed into action at right-back, but United were forced back early on, when Lukaku raced clear on the left.
It was exactly the kind of area where the Belgium striker had ran Chelsea ragged in the quarter final, but his first touch was heavy, and although he lifted the ball over David de Gea, Wayne Rooney was on hand to head off the line.
Emirates FA Cup highlights: Everton 1-2 Manchester United
United hit back though, with Marcos Rojo flashing a header wide from a free-kick and Jesse Lingard forcing a sprawling save from Joel Robles after ghosting through unmarked.
It was a thrilling, open game, and Lukaku had another fine chance, with De Gea blocking at his near post.
United then began a series of forays down their left-hand-side, with Rojo offering a decoy while Martial and Rashford took turns to run at Besic.
The ploy paid off on 34 minutes, when Martial drove into the box and pulled Phil Jagielka across, and while the England defender cleared the ball to an extent, it soon fell back to Martial.
The Frenchman darted towards the byline, and cut back for Marouane Fellaini to score against the club who once paid £15m to bring him to England.
United may look back on the 20 minutes that followed as the time when they should have put the match to bed, such was their possession.
But for all Everton’s struggles, they were given hope on 57 minutes when Fosu-Mensah’s covering tackle on Ross Barkley was adjudged a foul, and a penalty was awarded.
Lukaku stepped up, but although his spot-kick was firmly struck, De Gea dived to his right to pull off a superb save.
Barkley, James McCarthy and Tom Cleverley then all went close for Everton, before United’s rearguard finally gave in with 15 minutes remaining.
The substitute Gerard Deulofeu skipped down the right before crossing dangerously, and while Smalling did well to get to the ball before Lukaku, his touch defeated his own keeper as he sliced the ball into the net.
Lukaku, who had a torrid day until then, pounded the ground with delight.
But any joy for Lukaku and Everton was short-lived.
Herrera, who was booked just seconds after coming on after a professional foul on Barkley, took the ball with his back to goal, and under immense pressure, squeezed a through-ball towards the onrushing Martial.
The Frenchman’s first touch was classy, and his last absolutely deadly.
Everton (4-4-1-1): 1 Joel Robles; 17 Muhamed Besic, 5 John Stones, 6 Phil Jagielka (captain), 3 Leighton Baines; 12 Aaron Lennon, 15 Tom Cleverley, 4 Darron Gibson, 16 James McCarthy; 20 Ross Barkley; 10 Romelu Lukaku.
Subs: 19 Gerard Deulofeu for Lennon 70, 11 Kevin Mirallas for Gibson 90+4.
Substitutes not used: 24 Tim Howard, 2 Tony Hibbert, 8 Bryan Oviedo, 21 Leon Osman, 38 Matthew Pennington.
Manager: Roberto Martinez.
Goal: Smalling 75og
Manchester United (4-1-4-1): 1 David de Gea; 51 Tim Fosu-Mensah, 12 Chris Smaillng, 17 Daley Blind, 5 Marcos Rojo; 16 Michael Carrick; 9 Anthony Martial, 27 Marouane Fellaini, 10 Wayne Rooney (captain), 35 Jesse Lingard; 39 Marcus Rashford.
Subs: 25 Antonio Valencia for Fosu-Mensah 61, 21 Ander Herrera for Fellaini 87.
Substitutes: 20 Sergio Romero, 7 Memphis Depay, 8 Juan Mata, 29 Morgan Schneiderlin, 36 Matteo Darmian.
Manager: Louis van Gaal.
Goals: Fellaini 34, Martial 90+3.
Referee: Anthony Taylor.
Assistant referees: Stuart Burt and John Brooks.
Fourth official: Jon Moss.