The Brazil international struck in the 3-1 win.
“I’m really happy, really confident now and just trying to play my football again,” he said post-match. “(Manager Mikel Arteta said) go there, control the game and try to take the game to the final third and create chances for us.
“It was a tough one, we showed our qualities. I think we did really well, we won the game so really happy. We have the international now we have to go there and try to stay fit and think about the upcoming games. We’re ready and can’t wait until the Premier League is back again.”
Martinelli also said: “We know when someone opens the ball up, we know the areas that we need to go.
“It was an unbelievable ball from B, and I was there - a really good moment for me and a nice goal. I just tried to put it down, and I’m really happy with the goal.
“He’s a really nice guy as well so we’re really happy to have him here as one of the captains. He’s unbelievable, one of the best players in the world right now.”