The Russian playmaker kept his cool to convert Samir Nasri’s pass in the first leg of the Champions League clash at Emirates Stadium.
Arshavin’s winner completed a courageous Arsenal comeback and meant that the Gunners would head to Camp Nou on March 8 with a slender advantage.
"To score against Barcelona for any player is a very crucial moment, maybe in your career," Arshavin told the club's official website. "It doesn't happen a lot and especially [because] it brought a win."
The 29-year-old was used as an impact substitute by manager Arsene Wenger, coming on in the 69th minute for the more defensive-minded Alex Song.
Despite Wenger’s tactical ploy to bring the Russian on paying dividends, Arshavin is modest about the impact he had on the game.
"When I came on I didn't feel special, I was just calm, and when I had a chance I scored the goal," he added.
"I did not change the game, I just took my chance. If I changed the game I would say. When I was sitting on the bench it looked very tough for us because Barcelona always have a lot of possession - that is why you must be patient.
"After the game I was very excited but now it is in the past and we have to be focused on the next game."
Arshavin’s goal was his ninth of the season and he helped Arsenal record their first victory over the Catalan giants in six attempts.
