The unsettled Argentine, who coach Roberto Mancini said had told him he wanted to stay at the club, showed his importance with emphatic finishes either side of a Joleon Lescott header.
The win saw City leapfrog Arsenal and boost their chances of avoiding a playoff to reach Europe's elite competition.
The win moves Mancini's in-form side into a coveted automatic Champions League place with 68 points while Arsenal are fourth with 67 also from 37 games with one remaining.
"Every time we say he is important and a fantastic player," the City boss told reporters. "I think he will stay here next season. We don't have a problem. He told me that he wants to stay, he has a five-year contract."
Lescott doubled City's advantage eight minutes into the second half when he rose above goalkeeper Thomas Sorensen and headed into an empty net.
"It's important now that we gather our strength for the game at Bolton," Mancini told the City website.
"We had a fantastic gift on Sunday from Arsenal and now everything is in our hands and we can't lose ths chance."
