Pierre-Emerick Aubameyang score a debut goal And Sanchez Scored his first Goal for Man Utd!! Rate Their Performance! :)

Wenger saw Pierre-Emerick Aubameyang score a debut goal and Aaron Ramsey his first hat-trick as his side thumped a disorganised Everton.

However, Arsenal have not kept a clean sheet in eight Premier League matches, and finished Saturday's match five points adrift of a Champions League qualification place.

"Our challenge is to find a balance," Wenger said. "We're a very offensive team but need to find a balance between attacking and defending. That will be our challenge until the end of the season."

Aubameyang, a club-record £56m signing from Borussia Dortmund on Wednesday, chipped in from fellow new arrival Henrikh Mkhitaryan's pass as the home side led 4-0 by half-time.

Television replays showed the goal should have been ruled out for offside, although the visitors could hardly claim the decision made a huge difference to the match.

Everton conceded three times in the opening 20 minutes amid defensive chaos, with Ramsey touching in the opener from Mkhitaryan's cross.

Laurent Koscielny got in front of Aubameyang to head the second at the far post after Shkodran Mustafi glanced on Mesut Ozil's corner, before Ramsey scored a deflected third.

Aubameyang struck the fourth before half-time, prompting Everton manager Sam Allardyce to abandon his three-man central defence and revert to a back four.

Substitute Dominic Calvert-Lewin headed an Everton consolation from Cuco Martina's left-wing delivery, before Ramsey swept in his hat-trick goal from another low Mkhitaryan cross.

Wenger was pleased with Ramsey's showing, saying: "He is calm in finishing. He used to rush it. Over the years, I think he can get 10-15 goals a season."

However, Arsenal lost goalkeeper Petr Cech to a calf injury in a collision with Oumar Niasse as the striker hit the post in the second half.

After an uneventful first half, Romelu Lukaku gave United the lead on 55 minutes with a close-range volley.

Sanchez was then fouled by Huddersfield defender Michael Hefele to win a penalty and the Chilean, a January signing from Arsenal, stepped up to take the spot-kick.

The forward saw his low shot saved by Jonas Lossl, but made no mistake with the rebound to double United's lead on his home debut.

It was an emotional day at Old Trafford as United commemorated the 60th anniversary of the Munich air disaster with a minute's silence before kick-off.