SAN FRANCISCO – Late last season, after falling out of playoff contention, the San Jose Earthquakes brought Trinidadian youth international Cordello Cato to Northern California for a multi-week trial.

On Tuesday night, the Quakes probably wished they could have signed him.

Cato, whose rights were held by Seattle on a Discovery Claim, was the Sounders' hero at Kezar Stadium, delivering a first-half goal that put the three-time defending US Open Cup champions into the semifinals of this year’s tournament.

Seattle held off a furious second-half onslaught from San Jose, the MLS Supporters’ Shield leaders, and made Cato’s goal hold up for a 1-0 win.

The Sounders now will host Chivas USA in the semifinals on July 10 at Starfire Sports Complex in Tukwila, Wash.

It was the first win by the Sounders against MLS competition since May 9, perhaps hinting at a return to form for Seattle, who are on an 0-4-3 slide in league play.

Cato scored his first goal as a Sounder in the 19th minute, catching up with a lead pass originally ticketed for Seattle forward Sammy Ochoa just before it crossed the end line to the right of San Jose’s goal. Striking from an acute angle, Cato kept his shot low and slid the ball between the legs of San Jose goalkeeper David Bingham.

The Quakes, who have four comeback wins and three ties in MLS play this season, poured players forward following the insertion of Chris Wondolowski and Steven Lenhart in the 53rd minute, but never could find an equalizer.

Andrew Weber, whose contract option was not picked up by San Jose this winter, picked up the shutout in his USOC debut with Seattle.

In a game that grew more fractious in the second half, Quakes forward Alan Gordon received a red card in second-half stoppage time, and Seattle’s Eddie Johnson delivered a blow to San Jose reserve Jed Zayner after the final whistle.

The Sounders waited at midfield until security could safely escort them off the pitch and past an announced crowd of 7,219.

San Jose coach Frank Yallop sat seven usual starters, including Wondolowski, who leads MLS with 13 goals, and Lenhart, who has five. Joining them on the bench were goalkeeper Jon Busch, defender Jason Hernandez and midfielder Marvin Chávez. Injured midfielder Simon Dawkins was absent, and captain Ramiro Corrales got the night off.