The Gunners won 2-1 on Saturday, with Matheus Cunha's 85th minute goal for Wolves creating a tense finish.
“In the Premier League it's always like that," said Martinelli later. “You need to be ready because the game can change in one action. I don't think they were creating a lot of chances but as I said in one action, the game can change but I think we deserved the win.
“We did well and the most important thing is the three points, so we got it.
“We tried our best, we kept going, we didn't start to play like it was already won," he added. “As I said, we tried our best to score another goal, but we didn't score. But the most important thing is three points.