Wenger had to settle for a point from a 1-1 draw against Blackburn on Sunday at Ewood Park. But it was one more than Manchester United boss Sir Alex Ferguson was able to gain.
Arsenal now host Sven-Goran Eriksson's resurgent City on Saturday - a team that has won all three matches without conceding a goal.
Wenger said: "It looks like it (the league) will be tighter. We have only played two games of course.
"Away from home we are disappointed because we did not win but it is not a bad result to take a point at Blackburn.
"I am confident we will be up there but with whom I don't know."
United have taken two points from three games but Wenger expects their dip in form to be only temporary.
"I still think they will recover and come back," he said. "Three games played is not a lot."