Sarvas headed home a Robbie Keane cross in the 65th minute and Jimenez slotted a Robbie Rogers feed in the 80th for a 2-0 triumph that sent the Galaxy (9-7-3) into third place in the Western Conference, even on points with Portland – their opponent next Saturday in Oregon – but with more wins, the first standings tiebreaker. LA are four points off the lead.
Dallas (8-4-7) needed a victory to pull even with Western leader Real Salt Salt Lake, who they meet next Saturday in Frisco, Texas.
The Galaxy were dominant throughout an entertaining clash, outshooting Dallas, 22-6, and creating more than a dozen scoring opportunities while denying their foe more than a few looks at the net. Carlo Cudicini dealt with the best Dallas chance, leaping to parry a dipping 28-yard shot by Jackson Goncalves in the 76th minute.
Keane created the first goal, taking a long pass from Omar Gonzalez on the left flank, beatingStephen Keel to the byline and chipping in a ball that cleared Gyasi Zardes but found Sarvas running nearly parallel to the goal for the simple finish.
Jimenez, in the middle of the box, first-timed a ball Rogers sent from from the left byline for the second goal with 10 minutes to play. It was Rogers' first point with the Galaxy, and Keane also was awarded an assist.
Zardes had LA's best chance before the goal, a 61st-minute header from a short Jimenez cross that drew a leaping save from Dallas goalkeeper Raul Fernandez.
Rogers nearly scored his first Galaxy goal on two occasions. He was alone in Dallas' box from a long through ball by Gonzalez that Keane dummied in the 18th minute, but Fernandez made the save and Matt Hedges beat Zardes to the rebound. Rogers' shot in the 49th, after a diving Fernandez parried a Sean Franklin cross, got through the Dallas goalkeeper, but Jair Benitez easily cleared it off the goal line.
Keane fired high from just inside Dallas' box in the 36th minute, and Keel appeared to block a Zardes header with his arm in first-half stoppage, but referee Ricardo Salazar didn't acknowledge LA's calls for a penalty.
The Galaxy were without Landon Donovan, who is with the US national team for theCONCACAF Gold Cup, but Blas Perez skipped Panama's tournament-opening victory over Mexico at the Rose Bowl to play against LA.
With George John still sidelined with a hamstring strain, Dallas maintained the Hedges-Keel pairing in central defense, but Schellas Hyndman rotated wingers after Thursday's draw with Chivas USA, with Fabian Castillo taking Kenny Cooper's spot on the left and Je-Vaughn Watson stepping in for Jackson on the right.
FC Dallas returns home for a top-of-the-table clash with Real Salt Lake on Saturday night at FC Dallas Stadium.