GLENDALE, Ariz. -- Ryan Mathews is off and running this preseason, great news for the San Diego Chargers.
Mathews, slowed by two broken collarbones a year ago, carried 14 times for 57 yards and a touchdown, and the Chargers beat the mistake-prone Cardinals 24-7 for their first preseason victory under new coach Mike McCoy.
Mathews' performance came a week after he carried nine times for 45 yards against Chicago.
The Chargers blocked a punt, blocked a field goal and returned a fumble for a touchdown.
The Cardinals lost several players due to injury, including left guard Jonathan Cooper, the team's first-round pick who broke his left leg and was helped off the field in the third quarter.
Arizona's Rashard Mendenhall carried six times for 47 yards before leaving with an ankle injury.
Arizona's problems began at the end of its first possession when Darrell Stuckey blocked Dave Zastudil's punt and the Chargers recovered at the Arizona 34. But a false start penalty pushed San Diego back, and Nick Novak's 51-yard field goal try was no good.
After a Cardinals three-and-out, San Diego went 92 yards in 12 plays, using up 6:51 of the first quarter. Mathews dived over the middle into the end zone, the first points allowed by Arizona's first-team defence in the preseason. The drive featured an unnecessary roughness penalty against the Cardinals' Ronald Talley.
Early in the second quarter, Arizona rookie Tyrann Mathieu hit Rivers' arm as he threw and the ball popped into the air. Jasper Brinkley intercepted and lateraled to Patrick Peterson, giving the Cardinals the ball at their 47. The Cardinals drove to the Chargers 8-yard line, but on third-and-goal, Rob Housler dropped Palmer's pass in the end zone. Then Kwame Geathers blocked Dan Carpenter's 26-yard field goal try.
The wild second touchdown came a short time later.
The third pass interference penalty of the game against Arizona cornerback Jerraud Powers put the ball at the Cardinals 1. Mathews went over the middle, but the ball popped free. Cardinals safety Rashad Johnson picked it up but, in an ill-advised move, lateraled to Sam Acho.
A challenge by McCoy backfired and set up Arizona's touchdown.
Palmer threw over the middle to Andre Roberts, who dropped the ball. But McCoy challenged that it was a fumble, and indeed it was. However, officials ruled that Roberts, not the Chargers, recovered at the San Diego 16. On the next play, Palmer threw to Michael Floyd for the only touchdown for Arizona's first-team offence in the preseason.
The Chargers also scored on Fozzy Whittaker's 5-yard run and Novak's 50-yard field goal.
Ken Whisenhunt, fired as Arizona head coach after last season, returned to University of Phoenix Stadium as Chargers offensive co-ordinator.
--Cardinals NT Dan Williams hurt his right ankle on the double-fumble touchdown play and did not return. He was out earlier in camp with knee and ankle injuries.
--Chargers CB Johnny Patrick left in the first half with a concussion.
--Housler also left the game, with a right ankle injury.