Amorim has come under increasing pressure after a poor start to United’s season, so goals from Bruno Fernandes and Casemiro in a frantic first half played in lashing rain were welcome.
Those strikes came after Chelsea goalkeeper Sanchez’s mistimed tackle five minutes into the game and he was sent off for denying Bryan Mbeumo a goal scoring opportunity.
Fernandes marked his 200th Premier League appearance with his 100th goal for United and Casemiro nodded Amorim’s men further ahead before he needlessly picked up a second yellow card in first-half stoppage time.
Trevoh Chalobah’s header gave Chelsea hope in the second half and Amorim didn’t try to hide his disappointment after Casemiro’s red card.
Manchester United manager Ruben Amorim during the Premier League match at Old Trafford: Nick Potts/PA Wire.
John Aldridge’s Premier League verdict is in
“We can’t have the red card with Casemiro, but we like to complicate things for ourselves,” said Amorim.
“He’s [feeling] worse than me. We won so I will forget a little bit and he will suffer because he’s a top professional
“He understands what he did. He is experienced enough that that play should not be played like that. He cares too much.
Amorim went on to suggest this was a win his side badly needed after they started this game fourth bottom of the Premier Leagaue.
“It is really important because I understand the situation around this club,” said Amorim.
“We cannot forget that we suffer a lot when we are on top. We can lose against Grimsby, we can beat any team. I’m just thinking about the next one. It is really good to win. We need the urgency to win again, that is really important for us.
“We started the game really well, really aggressive. We were so aggressive in the second balls. We had the sending off with Casemiro, we like to complicate our game always but it was a good day. I felt the urgency and, of course, the sending off helped us. We had to be more clinical to finish the game off sooner.
“Every win, especially in this moment is important, against a great opponent.
“We started the game in the right way. Really aggressive. The red card helped us dominate the game but we were already there.
“We scored two goals and then we tried to complicate our game again. It’s always complicated with us. It should have been different this game.”
“We suffered in the end but we deserved the win.
“Our crowd, our fans are easy to please. If you give everything, they will be there. That is something our players need to understand. To have the crowd with us we just need to run, to fight and tackle.
“With this win we have to forget the good feeling of winning the game and get back to the urgency of feeling we need to win the next game.”
Chelsea boss Enzo Maresca told BBC Sport: “The red card changed the game after three minutes.
“After the red card for them, 10 v 10, it changed the game for us. We needed to start in a better way.
“They attack with five players so the idea was to defend with five players. You can defend with four at 11 v 11. The game probably changed after they conceded the red card also with Casemiro. We were much better.
“We need to start the game better. We cannot concede a red card at Old Trafford after three minutes.”