The Gunners squandered a great chance to bridge the gap on the league leaders by conceding first when Fernando Torres struck and then allowing Juan Mata's free-kick to clinch the points after Gervinho had levelled just before half-time.
The Ivory Coast striker admits it was a disappointing loss but says that Wednesday's Champions League fixture at home to Olympiakos is the most important thing to think about.
"It's a big disappointment," Gervinho told the club's official website. "These games against opponents for the title, we can't afford to lose them, especially at home. They count a lot in a season.
"We had a great team against us, with great players, technical players. Chelsea managed to keep the ball well and caused us problems.
"It would have been great for us to win it but we had no luck and we were not as good as our last game. It's a big disappointment. But we need to swallow this defeat and to focus again on Wednesday's game - because that is another big game."