Steven Lenhart also scored two goals to help the Earthquakes (7-1-1) extend their unbeaten stretch to 6-0-1 since losing to Houston on March 14.
Wondolowski moved past New York’s Thierry Henry and into the league lead with 10 goals. Wondolowski has scored 44 times since the start of the 2010 season.
D.C. United (4-3-3) snapped a seven-game unbeaten streak.
Lenhart opened San Jose’s scoring in the 19th minute by walking onto a blocked shot of teammate Tressor Moreno and slashing the ball home from 19 yards to tie the score at 1-1.
Wondolowski got on the board two minutes later, cashing in from just inside the penalty spot after a flurry of quick passes by San Jose. Morrow extended the Earthquakes’ lead to 3-1 in the 31st minute with a shot that caromed off D.C. midfielder Danny Cruz, leaving goalkeeper Joe Willis little chance.
Wondolowski scored again in the 64th minute, overpowering Willis with a header off Steven Beitashour’s cross, giving Beitashour five assists this year.
Woolard scored on a diving header in the 64th minute to pull United to 4-2.
Lenhart closed out his day by chesting home the rebound of Marvin Chavez’s ringing shot off the crossbar in the 74th minute to restore San Jose’s three-goal lead.
Salihi closed the scoring in the 88th minute after he took a lead pass and flipped his shot over San Jose goalkeeper Jon Busch.
De Rosario put D.C. up in the eighth minute with a steaming shot from nearly 30 yards, but United’s defense simply wasn’t up to the challenge.