Arsenal manager Arsene Wenger says Alexis Sanchez's performance in the Champions League 1-0 win over Besiktas shows he has the fighting qualities to succeed in the Premier League.
The £35m signing from Barcelona scored the only goal in Arsenal's narrow qualifying win at Emirates Stadium.
Wenger said: "Alexis had a good game. He was mobile, dangerous and showed great fighting spirit.
"These are qualities that will be important in the Premier League."
Sanchez's first goal for his new club, on the stroke of half-time, sent the Gunners into Thursday's group stage draw for the 17th consecutive season.
However, Wenger admitted Arsenal had anxious moments, especially after defender Mathieu Debuchy was sent off for a second yellow card 14 minutes from time - this after seeing Aaron Ramsey get a red card in the first leg.
He said: "We produced the performance we wanted on the tactical, technical and mental side that was required against a good team. We couldn't finish the game off so of course it was nervous for the last 10 minutes."
Besiktas felt they were denied two first-half penalties when Debuchy tackled Mustafa Pektemek and Jack Wilshere tangled with Ramon Motta in the area.
Wenger admitted: "Maybe we were lucky with one, the one with Jack, but I was also frustrated with the sending off. It was very harsh because Debuchy went for the ball. There was no intent to make a foul or stop the counter attack and he got the ball.
"We would have liked to have won the game earlier because it would have made it a lot easier but we wanted to qualify and we did it against a very good team."