Nicolas Pepe came off the bench to score a brace of free-kicks and seal a 3-2 win for Arsenal against Vitoria.
The Gunners had trailed 2-1 after goals from Marcus Edwards and Bruno Duarte, but Gabriel Martinelli pulled one back in the first half, before Pepe's match-winning cameo.
The win sees Arsenal move onto nine points in their Europa League group, and continued their perfect record in Europe so far this season.
After the game, Unai Emery heaped praise on Pepe. "New players usually need time for that adaptation and Pepe is a good player we believe in totally.
"He’s improving and tonight his two goals were very important. We are very happy for him.
"He was trying a lot of set pieces last week and I was expecting him to shoot after that.
"I think the most important is the three points and how individual players can improve."
After Pepe's second free-kick to win the game, midfielder Matteo Guendouzi was one of the first of his teammates to rush over and congratulate him, and the midfielder made a point of acknowledging the Ivorian's contribution to the crowd. The Frenchman first pointed in the air and then down to Pepe.
Arsenal welcome Crystal Palace to the Emirates on Sunday as they look to get their Premier League season back on track.
