The Republic of Ireland international had been out of action for a number of weeks after undergoing knee surgery, but showed no signs of slowing down with a decisive contribution, which brings his tally for the season to four goals in four MLS games.
"As you know, I'm always itching to get back playing and thankfully the rehab went well. I feel strong, I feel fit and I think I showed that today," Keane told Galaxy TV after the game.
"It's nice to be back, now roll on the next game."
Keane fired Galaxy ahead at the StubHub Center before Giovani dos Santos doubled their lead and the 35-year-old made it 3-0 before half-time.
Revolution came roaring back in the second half with goals from Kelyn Rowe and Juan Agudelo narrowing the deficit but Steven Gerrard's injury time goal took the pressure off the home side.
Speaking after the game, New England coach Jay Heaps rued the lack of attention paid to Keane by his defenders.
"It was poor marking on the first one," said Heaps. "The second one I have not seen yet, but that one was a little different because they were inside our six.
"But the first one was just bad marking and if you leave Robbie Keane open at the back post it's not nine out of 10. It's 100 out of 100."
The news of Keane's return comes as a boost to Ireland boss Martin O'Neill as he prepares to announce his squad for their final Euro 2016 warm-up friendlies against the Netherlands and Belarus.
The Boys in Green face the Netherlands at the Aviva Stadium on Friday, May 27 before facing Belarus at Turner's Cross on Tuesday, May 31.