Los Angeles (8-2-5) took the lead in the 70th minute when David Beckham delivered a cross into the center of the penalty area for Lopez, who gained control and sent a header past New England goalkeeper Matt Reis.
The Galaxy -- who notched their fourth straight win -- just missed on an earlier scoring chance in the 24th minute when Omar Gonzalez headed a Beckham corner kick on net but Reis was able to tip the ball off the crossbar.
New England (3-5-4) put on pressure during stoppage time, but a rebound try by Zack Schilawski was cleared off the goal line by the Galaxy's Landon Donovan.
Exploding whale video goes viral on Internet
Campus cop fatally shoots Texas student during traffic stop