David Luiz left Marouane Fellaini writhing on the floor in pain after catching the Belgian on the knee with his studs.
The Chelsea star was incredibly late in his attempt to poke to ball away from Fellaini and was shown a yellow card.
Gary Neville described the challenge as “shocking” on Sky Sports, while several Manchester United fans were quick to ask why Martin Atkinson didn’t send the Brazilian off.
The incident came minutes before half-time - and it’s a half-time that Jose Mourinho was desperate for.
On his return to Stamford Bridge, the Portuguese found his team 2-0 down inside 21 minutes. Pedro scored after 30 seconds and Gary Cahill doubled Chelsea’s lead when he blasted home from a corner.
Thierry Henry said it was a red card, Graeme Souness said Martin Atkinson bottled in. Twitter agreed entirely.
If Mourinho intended to secure a classic, snatch-and-grab win by defending resolutely and scoring on the counter, his plans were shot to pieces in the first minute.
Pedro managed to beat David de Gea to Marcos Alonso’s pass, losing Daley Blind in the process, before slotting the ball into the net.
Twenty minutes later Cahill heaped more misery on his former manager. United’s defence failed to clear Eden Hazard’s corner and the ball found its way to the England international, who smashed the ball past the helpless De Gea.
We can’t wait to hear what Mourinho has to say about Luiz’s challenge in his post-game press conference.
Did David Luiz deserve to be sent off? Let us know in the comments section below!