MANCHESTER -- Jose Mourinho says he is "keeping his feet on the ground" despite watching his Manchester United team thrash West Ham on the opening weekend of the Premier League season.
Two goals from new £75 million striker Romelu Lukaku helped United to a 4-0 win at Old Trafford which left Mourinho's side top of the table.
It was United's biggest opening-day win since beating Fulham 5-1 at Old Trafford in 2006 and Mourinho's biggest league win as Red Devils manager. United went on to win the title in the 2006-07 season, ending a four-year drought under Sir Alex Ferguson.
Mourinho, though, insists he is not getting carried away.
"We finished the [last] season winning the Europa League and qualifying for Champions League," he told a news conference. "We start the second season with a very good performance at home. We had many players on the pitch with a very good game. We have reasons to be optimistic.
"For me, years and years of experience and experience in the Premier League, my feet are on the ground and I am calm. Last season we were also top of the league in the first match and we finished sixth so this means nothing. It just means we played well and confidence levels will be high and now our challenge is to keep this confidence level."
There were plenty of positives for the United manager. Lukaku scored twice on his league debut for the club following his move from Everton, while Nemanja Matic, a £35m buy from Chelsea, ran the midfield in a manner that made it hard to believe he spent most of the summer training alone at Stamford Bridge.
Chelsea's 3-2 defeat at home to Burnley 24 hours earlier made Matic's performance even more noteworthy.
Mourinho said afterwards he had wanted Matic, who was named Man of the Match, at Old Trafford last season.
He added: "It depends on what is happening or what was happening behind doors and we don't know.
"The only thing I know is that of course with Chelsea money I brought him to Stamford Bridge because I thought he was a player with special qualities, and since I left I always thought he could be a perfect player for us, but I didn't disturb him, I didn't disturb Chelsea.
"I never thought it was possible unless something special was happening and his agent told me we could have him and we were very happy with that. We have him and we are very happy. He was a player this team needs."
West Ham were one of the 10 teams who got a point at Old Trafford last season, a statistic that cost United any chance of challenging Chelsea for the title.
In the 1-1 draw in November, United had eight shots on target but only scored once, while six on target this time produced four goals.
Lukaku has scored more goals against West Ham than any other team and took his tally to 11 in 13 games with a double.
Mourinho said: "Romelu scored in the Super Cup, scored twice today, he's playing well and he's working hard. He likes the team and the team likes him. Strikers can play phenomenally well, but if they don't score goals, the pressure's on them.
"So I think it was good for him to score and for all the guys arriving at new clubs who scored goals on their first games. It's always oxygen, it's happiness and confidence for them.
"Romelu knows we well. He knows sometimes strikers can play well but not score, but from me there will be no pressure. But today was very good and he was very effective, with the first goal especially."