The Borussia Dortmund playmaker has lauded his team-mate after they combined to beat the English side 2-1 at the Emirates Stadium in the Champions League
The 25-year-old Pole scored a clinical late winner in London to give BVB a priceless 2-1 Champions League victory, and the Armenia star believes his team-mate is one of the finest strikers on the planet.
"Lewandowski is simply magnificent," the former Shakhtar Donetsk man told the Bundesliga's official website.
"He was the best against Arsenal. How he ran, fought and coolly finished for 2-1 was indescribable. For me, he is one of the best strikers in the world."
Mkhitaryan opened the scoring for Dortmund, who were made to withstand heavy second-half pressure before Lewandowski's breakaway winner in the last 10 minutes.
"It was a really tough and important game for us. Playing away against such a strong side wasn't easy, but we dug in as a team and delivered a great performance," he said.
"Of course, the result is really good for us. I collected [Robert] Lewandowski's short pass. Then I noticed I had lots of space on the edge of the box. I controlled the ball and had a pop at goal.
"It's not important for me to be able to celebrate my goal come the final whistle. What's important is that I put in a reasonable performance on the pitch. My aim is to get better with every game because I still haven't hit top gear.
"I think the group will be decided on the final matchday. We have to raise our game for the next three matches and play better football. We have to hope we'll pick up a couple more points."