Strikes from Steven Naismith and Romelu Lukaku, along with a Mikel Arteta own goal, condemned Arsenal to a fourth consecutive game without victory as Everton moved a point behind Wenger's charges at Goodison Park.
Roberto Martinez's men boast a game in hand on Arsenal and are now in control of their own destiny when it comes to securing a first return to the UEFA Champions League since 2005.
While Wenger was critical of Arsenal's showing, he remains confident over reaching Europe's top club competition for a 17th successive season.
"I'm absolutely 100 per cent determined to fight to make the top four. It will be difficult but we still have a programme that is feasible," he said.
"Our performance was not convincing, either offensively or defensively. Everton were better than us and deserved to win and it's a very disappointing result and a very disappointing performance - the two go together.
"We have to regroup and come back to basics."
The Frenchman, who has seen Arsenal take just two points from their last possible 12 available, also suggested their experience in qualifying for the Champions League could serve them well.
"The fight is very open and not dependent only on us," he added. "Everton is in a strong position but we have been confronted with that before and it's down to how we respond to such a disappointing performance.
"I still feel we had a lot of the ball but were not really dangerous. Everton defended well and at the moment we lack the confidence to be really dangerous and lack penetration as well.
"The penetration and the incisiveness of our game is missing through the runs and through the passes. Those together make it difficult."
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