SAN DIEGO -- Cornerback Antoine Cason leaped for the ball as if he were a wide receiver, and the turnover derby was on.
The turnovers tied Jacksonville's team record and led to 17 points for the Chargers, who committed three turnovers and had a punt blocked.
"A lot of the time it takes the air out of the team and of course with the crowd behind us, it puts life into us," said Cason, who had two interceptions and forced a fumble. "It changes momentum."
The Chargers (1-1) bounced back from an embarrassing 21-14 loss at Kansas City on Monday night. The Jaguars (1-1) regressed following an opening win against Denver.
"It was a terrible day at the office," said Garrard, who threw four interceptions. "It's a day that you don't want to have. Honestly, if I could erase my memory from today, I would, but we can't."
The Jaguars' woes on the West Coast continued. Last year, they were outscored 61-3 in trips to Seattle and San Francisco.
Chargers rookie running back Ryan Mathews sprained his right ankle in the second quarter and didn't return. He also fumbled for the second straight game, one of San Diego's three turnovers. X-rays were negative and Mathews said he wanted to go back in, but coach Norv Turner said he wasn't comfortable having the rookie return.
Cason started the turnover fest by leaping for the ball as Garrard tried to split double coverage on the Jags' first possession. Brandon Siler and Kevin Burnett had the other picks for San Diego. Cason forced a fumble by Mike Sims-Walker that Burnett recovered. Antwan Applewhite forced a fumble by Maurice Jones-Drew that Paul Oliver recovered.
"We all know that if we give our offense the ball 15, 16, 17 times a game, they're going to put up at least three or four touchdowns," Burnett said. "That's our goal. A turnover is one less possession for them and one more chance for our dangerous offense to get on the field."
Rivers threw touchdown passes of 9 and 4 yards to tight end Antonio Gates in the first half, then hit Malcom Floyd on a 54-yarder in the fourth quarter. Mike Tolbert scored on runs of 2 and 1 yards. He gained 82 yards on 16 carries.
Rivers completed 22 of 29 passes, with two interceptions. It was his 16th career 300-yard day.
"We've got a great group," Rivers said. "Backs, tight ends, receivers. We're going to use all of them. We need all of them. Any given week, it could be their week."
"It was good that we were able to rebound and take control of the game," Rivers said. "But had the game been close, we would have looked back at those turnovers as having been key."
Jacksonville got its only touchdown with 37 seconds to play, a 3-yard pass from Garrard to Sims-Walker. Josh Scobee kicked field goals of 44 and 48 yards. The first was set up by a fumble by Mathews and the second was set up when Mike Scifres' punt was blocked by Rashad Jennings.
The Chargers had their miscues, too, but at least managed to find the end zone. Rivers moved San Diego 74 yards in six plays on the game's first drive, with Tolbert scoring on a 2-yard run.
The second quarter included a dizzying exchange of turnovers, plus the blocked punt. Cason's second pickoff, of a tipped pass, set up Rivers' 9-yard TD pass to a wide-open Gates for a 14-3 lead.
After Scobee kicked his second field goal, the Chargers moved 87 yards in eight plays, capped by Gates' 4-yard TD catch.
Oliver's fumble recovery set up Nate Kaeding's 41-yard field goal in the third quarter, and Burnett's interception set up Tolbert's 1-yard run early in the fourth. Burnett picked off a wobbly pass that was the result of Siler hitting Garrard.
Garrard made way for backup Luke McCown early in the fourth quarter. He came back, though, after McCown was shaken up.
Garrard was 15 of 23 for 173 yards.
"Your quarterback is your triggerman," coach Jack Del Rio said. "If he has a rough day, then generally speaking, it's going to lead to a rough day for your football team."
Turner said he gave game balls to the families of former coach Don Coryell and former defensive lineman Gary "Big Hands" Johnson, who died during the summer. ... The crowd was announced as 62,691. The Chargers' streak of sellouts was snapped at 48, including playoffs, and the game was blacked out locally. It was the first Chargers' blackout since November 2004. ... The blocked punt was only the second of Scifres' career.