Wondolowski's tally came in the 73rd minute off a diving header from within the Galaxy box following a Marvin Chavez corner kick and erased a 2-1 San Jose deficit.
The Earthquakes striker now needs two markers in next weekend's season-ending contest at Portland to best the current mark of 27 goals, set by Tampa Bay's Roy Lassiter in 1996.
Chavez also scored for San Jose (19-6-8), which Saturday clinched the league's best overall record when Sporting Kansas City played to a draw against New York.
2014: The Year in Fashion [PHOTOS]
UPI Sports Results for September 19, 2014