Adam Jahn scored the only goal of the game as the San Jose Earthquakes moved three points clear of the Houston Dynamo with a 1-0 victory at the BBVA Compass Stadium.
A bright start from San Jose almost brought an early goal for Chris Wondolowski, who could only head just wide of the target from a Shea Salinas cross.
The Earthquakes dominated for much of the first half as Houston settled for soaking up pressure, but the hosts were left thanking goalkeeper Tyler Deric when he kept out Matias Perez Garcia's free kick.
Houston could have broken the deadlock just after the break had Ricardo Clark's low strike not given David Bingham the chance to get a strong hand to the ball.
They were made to regret the miss less than 10 minutes later as San Jose took the lead through Jahn, who headed home after a quick free kick from Perez Garcia.
Houston were then gifted the chance to get back on level terms when Boniek Garcia evaded a couple of challenges before eventually being brought down by Bingham in the box.
However, Bingham quickly atoned for his error by pushing away the penalty from Giles Barnes as the Dynamo missed their best opportunity of the night from 12 yards.
Wondolowski could have doubled his side's advantage to make it a comfortable finish, but he could only send a header over from a corner.
Houston applied pressure late on, with Will Bruin striking the outside of the post from the edge of the box as San Jose secured all three points.