The French boss saw his players struggle to break down the 10-man Tigers after George Boateng saw red for a second bookable offence prior to the break, with Hull hanging on to a point until Nicklas Bendtner's injury time winner.
Asked whether victory at The KC Stadium was a defining moment in the Gunners' season, Wenger told ESPN: "We've had a few, but it was another one."
"I think we played very well, we started well, but then lost our focus and got punished," said Wenger, referring to Jimmy Bullard's equaliser from the spot after Sol Campbell hauled down Jan Vennegoor of Hesselink in the box .
On the decision to award Hull a penalty, the veteran manager expressed his belief that the match officials should have awarded an offside before Campbell's clumsy challenge, which was punished by a yellow card despite the protests of Hull's players who believed that the former Portsmouth defender had denied a clear goalscoring opportunity.
He added: "It was offside, I thought. He ran into Campbell and won a penalty.
"When it was 1-1, I knew we had the battle to win. We have the belief and we needed to fight."
Arsenal played much of the game against ten men after Boateng's tackle on Bacary Sagna saw the Dutchmen given a second yellow prior to the break, but Wenger seemingly accepted the motives of struggling sides who adopt a physical approach.
"Unfortunately he [Boateng] deserved it," said the Gunners' boss. "You can understand these teams don't want to go down from the Premier League, but it's down to the referee to make them respect it."
After midweek exertions in European competition, and with a long title challenge ahead, Wenger stated his belief in his side's ability to fight until the end after another late strike.
"I believe we a bit jaded - physically and mentally, " he said. "Hull were very strong and the pitch didn't help us.
"If you look at the number of goals we score in the last 15 minutes it shows how much strength we have."
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