Theo Walcott scored in the opening minutes against Udinese. Reuters

It didn't take long for Arsenal to get their 2011-2012 Champions League campaign off on a good note, as Theo Walcott scored in the opening five minutes to put Arsenal ahead of Udinese in the first leg, at Emirates Stadium.

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. 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.

Kieran Gibbs picked up a yellow card before the half. Udinese's Joel Ekstrand received a yellow as well for his foul to the back of Marouane Chamakh.