"It was a very poor day," Wenger told BT Sport. "Only the fans were good for 90 minutes. All the rest on our side, we were poor -- defensively, offensively -- and they (the goals) were all scored in slow-motion.
"Overall, on top of that, we were caught on two set-pieces at the start. But the performance was very poor and Liverpool played very well, so congratulations to them. We have to bounce back from that, and as quickly as possible.
"We were too open. Every acceleration from Liverpool was deadly for us and defensively, from up front to the back, we were not at the level that you are used to."
For Arsenal, it was the worst possible start to a run of fixtures that includes a league game with Manchester United on Wednesday, another meeting with Liverpool in the FA Cup next weekend, and a UEFA Champions League last-16 tie with defending champions Bayern Munich.
Asked how his side could put the defeat by Liverpool behind them, Wenger replied: "By the desire to give the right response. These are top-level sportsmen.
"We have shown since the start of the season we can do that, but of course it raises some questions today (Saturday) because we were caught many times and were a bit naive."
He added: "I'm confident we will (bounce back). Of course we produced a poor performance on a day when you couldn't afford it. But we have to think why, why it happened, and make sure it doesn't happen again."
Liverpool manager Brendan Rodgers was unsurprisingly delighted by his team's display, but he was reluctant to talk up their title chances.
"It was an incredible performance," he said. "It's not the first time we've been outstanding at home, but everything about us today was incredible. Everything was outstanding.
"We've been getting better and better. We've got a lot of young players, developing well. But for us it's just about improving."
A brace from Martin Skrtel put Liverpool 2-0 up inside ten minutes, with Raheem Sterling adding a double and Daniel Sturridge also finding the net before Mikel Arteta replied for Arsenal with a 69th-minute penalty.