Cesc Fabregas feels Arsenal have closed the gap on Barcelona, but admits they cannot afford to get complacent.
The Gunners secured a memorable 2-1 win over the Catalan giants on Wednesday to claim the upper hand in their UEFA Champions League second-round tie.
Victory at Emirates Stadium puts Arsene Wenger's men on course for the last eight, but they still have to go to the Camp Nou.
They came unstuck on Spanish soil in the quarter-finals last season, with Lionel Messi guiding Barca to a 4-1 success and a 6-3 aggregate win.
That performance still haunts Arsenal and club captain Fabregas admits they still have it all to do, even if they are better placed this year to progress than they were in 2009/10.
He said: "They don't lose many games. They are the best side in football history, in my opinion.
"But we have only played half of this tie. It's a nice compliment to us, but that's all.
"We have closed the gap on them from last year. We are one year older, we have less injured players."
Robin van Persie, who drew Arsenal level on Wednesday before Andrey Arshavin snatched a late winner, also accepts that the Gunners are a long way from celebrating further progress in Europe.
The Dutchman believes Wenger's men were slightly fortunate to take the spoils in midweek, but was glad to see their hard work rewarded against a side that dominated possession for long periods.
He said: "We had to play our own game. If you drop back they will beat you easily.
"We had to beat them with their own style. We got a bit lucky, but in the end we deserved to win."