It is the first time Wenger's men have beaten the Blues in the Premier League since October 2011.
"It's one of those moments in your life as a manager where you think 'today is a great day'," Wenger said.
"I felt that in the last three weeks, our team was on the way up. Today was a good test for us to see if that's real, if we could continue to move upwards.
"Would Chelsea stop our progression? Overall the quality of our performance today confirmed that we are on the way up.
"Yes, it's one of the best performances in recent years because it's one of the games where what we wanted to do worked very well."
Wenger admitted it was too soon to talk about markers for winning the title but believes his team's display proves they have the quality to challenge.
"It was relevant for us because it helps us to win a big game but between winning a big game and winning the Premier League is a long way to go," Wenger said.
"At the moment Man City looks to be well in front, but if we can maintain our performances and the quality of our performances and be consistent we might have a chance."