Manchester United's 3-2 win over Arsenal brought Louis van Gaal out of his dugout seat and on to the floor, but it was Marcus Rashford's latest brace that had the Old Trafford faithful on their feet.

The teenage striker followed up his Europa League debut double on Thursday night with two more goals in the first half against the Gunners as his incredible introduction to senior football continued.

The 18-year-old also set up Ander Herrera for his deflected third goal to leave stunned visiting boss Arsene Wenger admitting United could have unearthed a gem.

"The player who was surprising for me talent-wise was Rashford because of the timing of his movement and his intelligence," the Frenchman said. "His movement in the box was great and he could be a very positive surprise for Manchester United on what I've seen."

Having now scored eight times in their past two home games, Rashford's arrival on the scene has helped reinvigorate a United side that have failed to captivate their home supporters on numerous occasions this season.

Boss Van Gaal, often criticised for staying on the bench when things have been going wrong, was even coaxed out on to the touchline on Sunday, although it was his belief Alexis Sanchez had dived, rather than Rashford's brilliance, which prompted him to move to fourth official Mike Dean's side.

His attempt to emulate Sanchez's fall on the sideline was warmly received by the fans at Old Trafford, yet Van Gaal regretted the histrionics.

"That was too emotional - it is not good for the referee and the linesman and the fourth official," he admitted.

"It doesn't happen much normally - I have had a lot of criticism because I am sitting on my bench and now I am off my bench and I have lot of criticism because I'm doing that.

"I have apologised to the referee and the linesman and I hope everything is solved. I have to control my emotions and I have said that also to my players."

On Rashford, he added: ''I think his performance was better than the first match. Normally the first matches a debutant plays are good, but it is the consistency - he has to show it in the third, fourth, fifth match. But what he showed in his second match is special, I think.''

Sanchez was one of a number of Arsenal players who underwhelmed against their injury-hit hosts, with goals from ex-United striker Danny Welbeck and midfielder Mesut Ozil counting for nothing in the end.

The defeat left Wenger's men five points off pacesetters Leicester and three behind north London rivals Tottenham ahead of the final 11 games, not that their manager is conceding defeat in the title race.

"We dropped three important points but we have to show we are up for the fight and bounce back on Wednesday night," said Wenger, whose side host Swansea in midweek.

"We have to not feel sorry for ourselves. Mathematically, what it means, we will only know at the end of the season."