MANCHESTER - Romelu Lukaku quietened questions about his ability to deliver against the best opposition by scoring and setting up the winner for Jesse Lingard as Manchester United beat Chelsea 2-1 on Sunday.

Lukaku hadn't netted in any of his six previous matches against top-six Premier League opponents for United, leading to suggestions the Belgian can only turn it on against the smaller clubs.

However, he has now scored 22 times in all competitions since his $97 million move from Everton in July.

"It's not bad, but you can always improve," said Lukaku of his return so far.

"I want to do better for the team. At the end of the day, I'm at Manchester United and I want to win trophies. That's the most important thing."

United manager Jose Mourinho was effusive in his praise for Lukaku, whose performance epitomized the host's overall display after a fast start by Chelsea.

The Blues deservedly led through Willian's strike just before the half-hour mark as United failed to get the best out of Alexis Sanchez and Paul Pogba in a four-man diamond midfield.

But Lukaku got his chance six minutes before the break when he slotted home Anthony Martial's pass.

He nearly bagged a spectacular second when his overhead kick was turned over by Thibaut Courtois midway through the second half.

But Courtois was helpless when Lukaku floated in an excellent cross for England international Lingard to head home his eighth league goal of the campaign.

"I think he played fantastically well," Mourinho said of Lukaku. "He was a little bit lost, but then he went together with the team.

"The team was improving, improving, improving ... he ended the game with the image of a hand in the goal."

Morata misfires

But for a late change of course from United in the summer, Lukaku and Chelsea striker Alvaro Morata could have been lining up for opposite sides on Sunday.

The Spaniard was high on Mourinho's wish list before United eventually decided on swooping for Lukaku to pave the way for Morata to move to Stamford Bridge from Real Madrid for a club-record fee just a week later.

Morata scored the only goal when the sides last met in November, but has not hit the net in two months now as a lack of fitness and form has derailed his first season in England.

"Like the other players, he tried to put everything on the pitch," said Chelsea boss Antonio Conte. "For sure he can improve. He can improve a lot."

Conte defended his decision to give Morata the full 90 minutes on his first start for six weeks and instead replace the influential Eden Hazard 17 minutes from time.

"Hazard was a tactical decision," said Conte. "You have to keep the same performance for 90 minutes.

"We didn't have a great balance and every single player has to work with and without the ball, otherwise we lose our balance and lose the game."

Morata's best chance came after just four minutes when he turned Marcos Alonso's low cross against the crossbar.

He also had the ball in the net five minutes from time, but had already been flagged for a contentious offside decision that saw Conte intensify his calls for video assistant refereeing (VAR) to be introduced to the Premier League.

"This type of situation can change the final result," said the Italian.

"For this reason I am very positive about introducing VAR, especially in England.

"We have to have this system to help the referees avoid this big mistake."

Agence France-presse