Lukaku scored the third as Manchester United thumped Ronald Koeman's side 4-0 at Old Trafford.

After beating Jordan Pickford, Lukaku cupped his ear towards the visiting fans who had cheered when their former striker hit the wall with a free kick moments earlier.

Lukaku told Sky Sports: "It's another goal really, but we're really happy with the win and that we stay top of the league. That's the only objective for me this season.

"[The celebration] was just a bit of banter. I missed the free kick. I missed then knocked in the rebound. It's just football."

Lukaku missed a good chance in the first half before netting his seventh goal in as many games for United this season.

Mourinho said: "He knows that from me there is no pressure for goal scoring, my pressure is for the tactical plan, for the organisation of the team, and he knew that I was totally happy with him so no reason to lose any confidence.

"His goal -- the second [goal] was the most important, not the third -- it's nice for him. Strikers always like to score goals."

Wayne Rooney, returning to Old Trafford for the first time since re-joining Everton in the summer, would have also scored against his former club but for a smart save from David De Gea shortly after half-time.

The 31-year-old got a standing ovation from the United fans when he was substituted in the 82nd minute and Mourinho said afterwards the reception had been well deserved.

He added: "I didn't need to ask, it's the nature of English fans, of big clubs, when a player is big in the club and has an important part of the club history, every club in England does that.

"I can only speak about the Bernabeu and Old Trafford, in both stadiums when we got former important players, the reception is normally phenomenal. He's at home and I believe he will be back home."

Despite leaving on the end of a heavy defeat, Koeman said he had been impressed with former United captain Rooney.

He said: "He was very good. He was clever and we need more players of that because he did every decision, he lost maybe two or three balls in the midfield that is not Wayne but overall his performance was really good."