GLENDALE, Ariz. -- First, Quentin Jammer swatted the ball out of Anquan Boldin's hands to prevent a touchdown.
Moments later, Antonio Cromartie stepped in front of Larry Fitzgerald in the end zone for an interception to thwart another Arizona scoring try.
San Diego's cornerbacks had a nice night against Kurt Warner and the Cardinals in the Chargers' 17-6 victory Saturday night.
"That's one of our biggest focuses," Cromartie said. "Do whatever you've got to to keep them out of the end zone. We did that."
The Cardinals have just one touchdown in two preseason games, and that on a drive directed by the fourth-string quarterback last week against Pittsburgh. But coach Ken Whisenhunt says he's not too concerned because the team is moving the ball and isn't developing a specific game plan for opponents, like it will do in the regular season.
"I'm disappointed that we haven't had more touchdowns, obviously," he said, "but I will say this, we haven't game planned in the red zone. A lot of times when we game plan in the red zone we're one of the best teams in the NFL, because we put our players in a position to best give them a chance to win.'
The Cardinals starters managed just a field goal on Saturday night, set up by a game-opening 89-yard kickoff return by diminutive rookie LaRod Stephens-Howling. Stephens-Howling, fighting just to make the team, also had a 63-yard return.
The sacks and kickoff coverage breakdowns were uncharacteristic for the Chargers.
"The things we take a lot of pride in around here," coach Norv Turner said. "...Tonight our guys saw we have some work to do."
Warner completed 6 of 13 for 80 yards in Arizona's first home game since its Super Bowl appearance. Cromartie's play came after the Cardinals had driven to the San Diego 13.
"I just read the quarterback's eyes," Cromartie said. "He stared Fitzgerald down the whole time so I just jumped the route."
Warner disputed Cromartie's version of the play.
"That's one of those routes where I don't even look at Larry until I'm going to throw it," Warner said.
Philip Rivers was 5-for-7 for 116 yards in a little more than 1½ quarters for San Diego but was sacked four times. He left after directing the team to its first touchdown.
LaDainian Tomlinson, playing in the preseason this year for the first time since 2005, gained 18 yards in eight attempts and caught two passes for another 18.
"I think it was just good to get in there and start to get a rhythm," said Tomlinson, who had four carries in the preseason opener against Seattle.
Brian St. Pierre, given a chance by Arizona coach Ken Whisenhunt to compete with Matt Leinart for the No. 2 quarterback job, replaced Warner and was 6-for-15 for 79 yards and an interception.
Leinart came in with 8:36 to play after the Cardinals stopped San Diego on the Arizona 1-yard line. He drove the team to the Chargers 11 but his fourth-and-three pass was incomplete.
Nate Kaeding kicked a 56-yard field goal for San Diego, a yard shy of his longest, a 57-yarder at Tampa Bay last season.
San Diego improved to 1-1 in the preseason, Arizona is 0-2.
One bright spot for the Cardinals' first-team offense was the running game, worst in the NFL last season. Tim Hightower carried nine times for 42 yards. Running back Beanie Wells, Arizona's first-round draft pick, suited up but did not play. He has missed both preseason games after spraining his right ankle in his first practice.
"It is disappointing because we had some opportunities we didn't capitalize on like we wanted to," Warner said, "but there is going to be a lot of stuff we can learn from tonight. We will get better and be all right in a couple of weeks."
Rivers threw a 49-yard pass to Legedu Naanee on San Diego's first play, but the threat ended with consecutive sacks by Darnell Dockett and Karlos Dansby.
Rivers' short pass to Darren Sproles turned in to a 36-yard gain to set up San Diego's first touchdown. Rookie Greg Toler was called for unnecessary roughness for running in to Sproles as he stepped out of bounds. That moved the ball to the Arizona 4, where Michael Bennett bounced outside for the score.
Fitzgerald did not catch a pass. ... The Chargers were without three players listed as starters - wide receiver Vincent Jackson (sprained finger), defensive end Jacques Cesaire (calf) and safety Steve Gregory (ribs). ... Arizona's No. 3 wide receiver Steve Breaston, usually the kickoff and punt returner, was out with an injured knee.