Romelu Lukaku hailed his debut double for Manchester United as a dream come true as the Belgian striker inspired his side's 4-0 demolition of West Ham on Sunday.
Lukaku joined United from Everton for a British record £75 million ($96 million, 82 million euros) in the close-season and the 24-year-old wasted little time starting to repay that huge fee.
Accelerating on Marcus Rashford's 33rd minute pass, Lukaku drilled a powerful strike in off the post to put United ahead in their Premier League opener at Old Trafford.
The former Chelsea forward struck again in the 53rd minute with a powerful header from Henrikh Mkhitaryan's free-kick.
Anthony Martial and Paul Pogba scored in the closing stages to send United to the top of the table at the end of a memorable afternoon for Lukaku.
"To play in front of such a crowd is a dream come true but most importantly is the three points," he said.
"When you play for Manchester United, you have a job to do and mine is to score goals. It is promising.
"The manager wants me to be a leader for the team and create as much as I can. We work hard in training and it is paying off.
"The fans want to see attractive football and we have to stick to that. They will be pleased today.
"It is just the start, we need to keep working to the manager's plan."
Lukaku's muscular performance recalled Didier Drogba's finest moments under Mourinho during their successful partnership at Chelsea.
And Mourinho is confident Lukaku will bring a much needed menace to the United attack as they chase the title.
"The Premier League taught me that you need to be adaptive to perform immediately," he said.
"Romelu is aggressive so he improves our team and the way we work. We have conditions to be a better team this season than last season.
"Romelu can gives us aerial threat, protect the ball and a good way out for us.
"We are not on the moon but it is a good start. I enjoyed the confidence levels."