Arsenal piled more misery on the under-pressure Toffees boss Ronald Koeman with a dominant display at Goodison Park, cruising to a 5-2 triumph on Merseyside.
It provided a fitting response to their defeat at Watford last time out and Ozil – who could well leave in the January transfer window with his contract expiring at the end of the season – put on a scintillating showing on his return to the starting XI.
"I would say [he is back to his best]," Wenger told Sky Sports after his side secured a first away win of the league season.
"I told him after the game that a fit Ozil is completely different. If you're not at your best physically, no matter how good you are, you are at a handicap.
"It's very difficult to single out any performances as everyone played very well. It was important to get our first win away from home."
Arsenal started on the front foot, though a stunning Wayne Rooney strike saw Everton teak the lead against the run of play.
However, the Gunners responded – Nacho Monreal levelling before the interval, while Ozil headed in Alexis Sanchez's cross shortly after the restart.
Idrissa Gueye's dismissal for a second bookable offence left Everton even more vulnerable and Arsenal soon had a third with Ozil turning provider for Alexandre Lacazette, with Aaron Ramsey and Sanchez adding further gloss to the victory either side of Oumar Niasse's scrappy effort to mark Wenger's 68th birthday in style.
"After Wayne Rooney's goal, we should have been 2-0 or 3-0 up, but we were 1-0 down," Wenger continued.
"We didn't panic and maintained our focus. Once we equalised, it was all us for the rest of the game.
"I was [concerned] because recently we've been punished for every mistake we make away from home. But I knew there was a long time to go.
"Our away performances this season have not been rewarded."