JAMES MADDISON was hooked off at half-time in a bold tactical switch by Ange Postecoglou.
Tottenham were drawing 1-1 with West Ham after the opening 45 minutes when the Spurs boss made the surprising decision.
TNT Sports claimed the move was tactical and commentator Ally McCoist said Maddison had a quiet first-half and the gaffer may have decided "enough is enough".
The substitution saw Dejan Kulusevski move higher up the pitch, with defensive midfielder Pape Sarr replacing the England star.
Maddison created five chances before the break - three more than the entire West Ham team managed - and he completed more passes than any other player.
He also got the assist for Kulusevski's goal before he was taken off.
Maddison reappeared and looked glum with his hood up as he sat on the bench.
But the sub proved to be a stroke of genius by Postecoglou as Spurs scored three in a second-half blitz.
They netted them in a rampant seven-minute span to go 4-1 up, as the match would finish.
Yves Bissoma put Tottenham ahead before Jean-Clair Todibo turned in an unfortunate own goal - although goalkeeper Alphonse Areola was later harshly credited with the blunder by the Premier League.
FOOTBALL FREE BETS AND SIGN UP DEALS
Son Heung-min, on his return from injury, then grabbed the fourth.
Fans praised Postecoglou's game-changing sub, with one saying: "Full credit to the gaffer. Sarr on for Maddison has worked wonders."
Another added: "A genius substitution."
On taking off Maddison, Postecoglou explained: "West Ham asked certain questions in midfield areas. I just thought Sarr's running power would help."
As well as losing 4-1, West Ham now face the prospect of being without Mohammed Kudus for three matches.
The Hammer winger was sent off against Tottenham after a wild brawl in Saturday's London derby.
Kudus was given his marching orders after pushing Micky van de Ven in the face following a tussle for the ball in midfield.
The 24-year-old caught Richarlison with a flying arm during a wild melee, sending the Spurs striker to the floor.
Sarr also weighed in to try and calm proceedings and appeared to be caught in the face as Kudus lost his cool.
He now faces a three-match ban after his yellow card was upgraded to a straight red following a VAR check.