Theo Walcott scored in the opening minutes to give Arsenal the 1-0 lead. Reuters

It didn't take long for Arsenal to get their 2011-2012 Champions League campaign off on a good note.

Theo Walcott scored in the fourth minute to put the Gunners ahead of Udinese in the first leg, at Emirates Stadium, and that's all the Gunners would need in the 1-0 victory.

Walcott, who was expected to play a major role in the match with Robin van Persie inactive due to suspension, scored off an Aaron Ramsey cross on the right side, as the Gunners completely dominated the early portion of the match.

At about the 10th minute, Arsenal almost received a two-goal cushion, but Gervinho couldn't make contact with the ball near the far post off a corner kick.

Udinese grew increasily confident in the later part of the half, and followed that up with an impressive second half that had Arsenal on their heals. The Serie A club nearly scored in the 26th minute when striker Antonio Di Natale couldn't follow the rebounded save by Wojciech Szczesny, who had just blocked a shot by Pablo Armero.

Di Natale had a pair of chances to equalize. One of note was a curling shot in the 74th minute that Szczesny palmed behind for a corner.

Arsenal controlled the ball for 55 percent of the match. Udinese took nine shots, and two were on goal. Arsenal took eight shots, and five were on goal.

Meanwhile, bad luck continues to find its way into Emirates. Kieran Gibbs apparently suffered a hamstring injury and was replaced by Johan Djourou at halftime. After about 10 minutes, Djourou exited the match with an injury as well, and was replaced by youngster Carl Jenkinson.

The second leg will be on August 24th at Stadio Friuli.