The Galaxy captain scored in a 4-1 victory over Costa Rican side Herediano to help send the club into the semi-final of the Concacaf Champions League
Galaxy took the lead on 18 minutes through an Omar Gonzalez header, while second half goals from Jose Villareal, Jack McBean and Keane secured the win for the MLS side.
Villareal scored on the 69th minute to put Galaxy 2-0 up, while Keane latched onto a through ball from Michael Stephens in the 83rd minute before slotting home. Herediano scored through Elias Aguilar on 85 minutes, but Jack McBean's stoppage time goal made the final score 4-1.
Speaking after the game, Keane praised Villareal's decisive goal and suggested that it could be a 'big season' for the midfielder.
"He has done well. As I've said before, it could be a big season for him," Keane told the club's official website.
"He stepped up tonight and showed his quality. He scored a vital goal at an opportune moment so it was good for us."