BILBAO, Spain: Arsenal began their Champions League campaign with a 2-0 win away to Athletic Bilbao on Tuesday, with Gabriel Martinelli making an immediate impact from the bench to open the scoring and another substitute, Leandro Trossard, netting the second. Mikel Arteta’s side, beaten at the semifinal stage last season by eventual winners Paris St. Germain, were the better team on the night, but labored to put away Athletic who were backed by a boisterous San Mames stadium, until the substitutes arrived.

Minute-by-minute report: This season’s league stage kicks off in Bilbao. Join Barry Glendenning

Gabriel Martinelli scored less than a minute after coming on then set up Leandro Trossard as Arsenal won 2-0 at Athletic Bilbao