The managerless visitors were watched by prospective boss Ole Gunnar Solskjaer from the Emirates Stadium directors' box and frustrated Wenger's title chasers as Theo Walcott, Jack Wilshere and Per Mertesacker all came close to breaking the deadlock.
It remained intact until the 89th minute, when substitute Nicklas Bendtner smashed home from close range after David Marshall saved well from Bacary Sagna's header.
Walcott burst through the Cardiff defence in injury-time to net a delicate chip and return Arsenal to the Premier League summit following a 3-2 victory for closest rivals Manchester City in the day's early kick-off at Swansea City.
"We needed to be patient against a very good Cardiff side," Wenger told BBC Sport.
"They did work absolutely hard, their new manager was in the stands. They deserve credit and were a bit unfortunate to lose in the end.
"I think we were mature, intelligent and resilient. Maybe it is a consequence of the number of games we have played.
"We know we have to play 10 home games and we want to make this place a fortress and take the points no matter what the others do.
"If we can manage to do that we will be in a very strong position."