Hester ran for two touchdowns and the Chargers defeated the Dallas Cowboys 31-17 Saturday night in the first preseason game for each team.

San Diego's third-round draft pick out of LSU, Hester scored on runs of 1 and 2 yards. He gained 49 yards on 13 carries.

Hester is competing with Darren Sproles to replace Michael Turner as the backup for two-time defending NFL rushing champ LaDainian Tomlinson. Sproles gained 7 yards on five carries and had a 5-yard touchdown run, one of three first-half rushing TDs for San Diego.

Tomlinson, who has a slight strained groin, rarely plays in the preseason and did not suit up. Tomlinson was not scheduled to play before he was hurt late in the week. In his career, Tomlinson has just 14 preseason carries.

San Diego quarterback Philip Rivers played three series and directed the Chargers to a pair of touchdowns. Rivers completed five of six passes for 54 yards and left early in the second quarter with a 14-7 lead.

Cowboys quarterback Tony Romo looked sharp in his only series as he lead Dallas to the game's first touchdown on an 8-play, 54-yard drive. Romo completed all three passes for 33 yards. His 16-yard pass to Patrick Crayton to the 3-yard line set up Deon Anderson's 2-yard scoring run.

The game was the Dallas debut of cornerback Adam Jones, signed as a free agent in the offseason. Although he did not start, Jones saw considerable action into the second half of the game.

Jones, who sat out last season after being suspended by NFL Commissioner Roger Goodell, was called for a pass interference call in the third quarter that moved the ball to the Cowboys' 2-yard line, setting up Hester's 2-yard run.

The game also was the first for Marion Barber as Dallas' starting running back. Barber, a Pro Bowl selection last season, gained 24 yards on four carries while also playing one series.

Felix Jones, the Cowboys' first-round draft choice out of Arkansas, carried 6 times for 32 yards.

San Diego also scored on a 1-yard run by Mike Tolbert and on Nate Kaeding's 53-yard field goal to lead 24-10 at halftime.

Notes: The Chargers played without six injured starters, including Pro Bowl TE Antonio Gates. Gates is still recovering from offseason toe surgery. .. San Diego scored 14 points off Dallas turnovers. ... Tennis star Rod Laver was in attendance.