The Germany international turned in an outstanding first-half display at the Stadium of Light as the Gunners claimed a 3-1 win, although in controversial circumstances which saw Black Cats boss Paolo Di Canio sent to the stands as time ran down.
Wenger said: "He [Ozil] was like the team - he had an outstanding first half and dropped physically in the second half.
"He was sick on Thursday night and I decided only today to play him, this morning. He had a stomach bug and didn't feel well.
"He dropped a bit physically in the second half, but his first half was outstanding."
Ozil needed just 11 minutes to make his mark, effortlessly pulling Kieran Gibbs' long ball out of the air and crossing for Olivier Giroud to sweep home the opening goal.
Theo Walcott wasted two glorious opportunities, both of them set up by Ozil, to beat keeper Keiren Westwood and then headed wide from Giroud's cross with Sunderland, who had earlier hit the bar through Modibo Diakite, in disarray.
However, half-time substitute Craig Gardner dragged the home side back into it with a 49th-minute penalty after Adam Johnson had been tripped by Laurent Koscielny, and the visitors found themselves on the back foot for the first time.
Aaron Ramsey volleyed Wenger's men into the lead with 67 minutes gone and then sealed the win nine minutes later, but not before referee Martin Atkinson had intervened.
Jozy Altidore and Bacary Sagna became embroiled in a wrestling match which the United States international eventually won before stabbing the ball past keeper Wojciech Szczesny.
Source: PA
Source: PA