Javier Morales scored his ninth goal in 15 career meetings with San Jose and Real Salt Lake beat the Earthquakes 1-0 on Sunday.
Real Salt Lake (2-0-2) and the New York Red Bulls (2-0-1) are the only MLS clubs without a loss this season.
Morales' free kick in the 44th minute deflected off the wall, landed back at his feet and he smashed the rebound past David Bingham for his second goal of the season.
San Jose's Sanna Nyassi fed Adam Jahn inside the 6-yard box, but Jahn's tricky backheel attempt went wide. Jahn rolled a breakaway chance in the 54th minute directly to RSL goalkeeper Nick Rimando.
Shaun Francis went to the San Jose (2-3-0) locker room in the 38th minute after a head-to-head collision with RSL's Jordan Allen.
U.S. men's national team coach Jurgen Klinsmann and Indianapolis Colts quarterback Andrew Luck were in attendance at the new Avaya Stadium.
Jalil Anibaba and Krisztian Nemeth scored in second-half stoppage time and Sporting Kansas City rallied to beat winless Philadelphia 3-2 on Sunday.
Philadelphia (0-3-2) failed to convert a one-on-one opportunity with the goalkeeper in the 88th minute for a two-goal cushion and Sporting KC (2-1-2) took advantage with goals in the 91st and 94th minutes.
Anibaba headed in the equalizer and Nemeth redirected a corner kick for the go-ahead goal.
It's the seventh time in MLS history that a team has trailed entering stoppage time and prevailed.
Philadelphia got on the board in the 3rd minute when a corner kick sailed over goalkeeper Luis Marin and bounced off Jacob Peterson for an own goal. It was the earliest goal ever conceded by Sporting KC.
Sporting's Dominic Dwyer headed in Benny Feilhaber's corner kick in the 16th minute for his first goal of the season. Philadelphia retook the lead three minutes later when Fernando Aristeguieta headed home Sebastien Le Toux's free kick.