SAN DIEGO -- The second preseason game of 2012 finished with a bang as the San Diego Chargers scored 21 unanswered fourth-quarter points on the way to a 28-20 victory over the Dallas Cowboys on Saturday night.

Turnovers were a big part of the game on both sides of the ball for the Cowboys.

Stephen McGee had two -- a fumble and an interception -- but the defense converted three, including two interceptions from cornerback Brandon Carr. Linebacker Orie Lemon recovered a fumble.

What it means: Well, the Cowboys (1-1) should be happy their first-team offense produced a score, and the first-team defense is looking like a playmaking unit, something defensive coordinator Rob Ryan is seeking. But the depth at certain spots -- offensive line, for example -- remains an issue. However, Kevin Ogletree might have emerged as the No. 3 wideout with a strong performance. He finished with four catches for 60 yards. Cole Beasley came on late against the Chargers' backups and had seven catches for 104 yards.

First-team offense produces: After getting just one first down against Oakland in the first preseason game, the Cowboys' first-team offense produced a field goal and six first downs. The run game, which struggled against Oakland, looked good Saturday. Running back DeMarco Murray had two five-yard runs and Felix Jones picked up runs of six and eight yards. Tony Romo did face some pressure in the passing game but completed 9 of 13 passes for 75 yards and wasn't sacked. Dez Bryant made an outstanding one-handed grab in the back of the end zone, but a penalty wiped it out and the back judge said Bryant didn't get both feet inbounds.

This is why you pay him: Cornerback Brandon Carr is earning his money, and while it's just the preseason, the $50.1 million corner did come up with two interceptions. Carr picked off a deep pass and tipped another pass three times before securing it for a second pick. Carr has been outstanding in practices, and when challenged by the Chargers he responded with a strong performance.

Claiborne debuts: First-round pick Morris Claiborne made his NFL debut Saturday night. He started and made two tackles. Claiborne had missed the offseason practices as he recovered from wrist surgery and was absent for training camp time because of a sprained knee. But Claiborne was on the field Saturday for his first games since he was at LSU.

Tough night for McGee: This week, coach Jason Garrett said he wanted to keep three quarterbacks, if he could. That probably sealed a roster spot for Stephen McGee. But McGee struggled Saturday night. He didn't have the protection he needed on some throws, but he made a poor throw on a deep ball that was intercepted, and he haired another ball that was broken up. McGee was hampered by a sideline drop and when under pressure he skipped a pass to Raymond Radway. In the middle of the fourth quarter, McGee avoided a corner blitz and completed a 13-yard pass to Andrew Szczerba. McGee lost a ball when he was hit from the blind side with 5:42 remaining in the game. He finished 9-for-16 for 86 yards and one interception.

First glance at who played well: Carr, Kyle Orton, Murray, Felix Jones, Victor Butler, Ogletree and Beasley.

First glance at who struggled: Teddy Williams, Akwasi Owusu-Ansah, Dan Connor, McGee and Tim Benford.

Notes and other tidbits: Jay Ratliff (foot) and Jason Hatcher (hamstring) did pregame warmups in full uniform but didn't play. It wouldn't be a surprise if either player returns for the St. Louis game next week. ... L.P. LaDouceur and Charley Hughlett shared the deep snapping duties. ... P Chris Jones fumbled a snap but ran for a first down. ... Mario Butler played safety and corner, but missed a tackle on a deep pass while playing safety. ... The game was blacked out on television in Southern California because the game wasn't sold out.

Who's next?: Cowboys will spend a few days here and scrimmage the Chargers Monday and Tuesday before returning home Wednesday. Cowboys have their preseason home opener against St. Louis next Saturday.