The Republic of Ireland international netted in the 21st and 34th minutes of the Western Conference semi-final second leg as the reigning champions overcame a one-goal deficit to beat Supporter's Shield winners San Jose Earthquakes 3-2 on aggregate.
The first leg at The Home Depot Center on Sunday ended 1-0 to the Quakes but the Galaxy managed to knock the minor premiers out of the running by booking their spot in the Western Conference Championship final and Keane's performance was not lost on LA boss Bruce Arena.
"Robbie's a great player," Arena said. "Robbie, since he's come back from the European Championship, has been the best player in the league.
"He scores big goals, he's competitive, he's bought into MLS, he likes LA, he's a great leader on our team and, when the whistle blows, he's ready to play. He's a great competitor."