The former Liverpool captain came off the bench to score in stoppage-time as Bruce Arena's men beat the New England Revolution 4-2 at the StubHub Center.
Galaxy skipper Robbie Keane, who was playing his first game since undergoing knee surgery in late March, opened the scoring in the 13th-minute before Giovani dos Santos doubled the hosts’ advantage 11 minutes later with a stunning volley.
Keane tapped in his second in first-half stoppage-time to give LA a three-goal lead, but the Revs came storming back after the break and scored twice in the space of just three minutes thanks to excellent strikes from Kelyn Rowe and former Stoke City signing Juan Agudelo to set up a nervy final 20 minutes.
LA secured the three points in the closing stages, however, when Gerrard, who had come off the bench to replace Keane in the 60th-minute, collected a pass from Mike Magee on the edge of the box before bursting through the opposition defence and looping his shot into the back of the net.
The 35-year-old midfielder was only fit enough to start on the bench after missing the previous weekend's 1-1 draw at Sporting Kansas City with a knock, but he was pleased with his performance overall – even if the Revs did start coming back into the game following his introduction.
“Yeah, it was not nice at the beginning,” Gerrard told LAGalaxy.com after the win. “I was thinking, ‘Is this all my fault?’ It didn’t go well, the 30 minutes when I came on they came back into the game.
“They were showing an awful amount of more energy than us at the time. It was nice at the end to finish the game off and a good three points for us in the end.
“Physically I am fine. I probably could have played a bit longer but Bruce [Arena] obviously thinking further down the line, we have a game coming up in 72 hours so I think it was sensible to just play 30 today and be available to more minutes come Wednesday.”
Sunday’s victory leaves the Galaxy sitting in second place in the Western Conference ahead of Wednesday’s trip to the Philadelphia Union, having taken 18 points from their opening nine games with five wins, three draws and just one defeat.