SAN FRANCISCO -- Looking to nit-pick a team after a 29-point victory? The Chargers' shaky defensive showing in the first half of Sunday's 48-19 win over the San Francisco 49ers at Monster Park is enough to leave a few brows furrowed.

For a team that entered play with the league's top-ranked defense and had allowed just 36 points through four games, the Chargers were all but carved up early. Through two quarters San Francisco had rushed for 56 yards and quarterback Alex Smith had passed for 132 more and a pair of scores.

The lapse only lasted for 30 minutes of play. Still, the 274 yards the Chargers allowed overall was the highest total for any opponent this season.

"We talked so much about what our goals are and we came into this game ranked No. 1, so to come out in that first half and give up 19 points is not what we wanted to do," said defensive end Luis Castillo. "But we're excited to get the win and get the chance to go and prove ourselves next week."

Said linebacker Shaun Phillips: "It's disappointing, because we look to shut every team out. But we know this is the NFL and that's not going to happen. So it was a disappointment to ourselves, but what erases disappointment is a win."

The Chargers were also in the mood to give credit. Linebacker Donnie Edwards said San Francisco's first half success was attributable to the unpredictability of offensive coordinator Norv Turner's attack.

"There were different wrinkles in their scheme," said linebacker Donnie Edwards. "Norv Turner does a great job of scripting their plays and moving guys around, giving different looks that we haven't seen.

"Once we settled down and we understood it, then we played well."

Castillo pointed to screen passes and a second quarter reverse after a direct snap to running back Frank Gore as part of the 49ers' game plan that had the Chargers in a haze.

But they eventually found a counter punch.

Phillips played a large part in stemming the momentum just before the unit regrouped with defensive coordinator Wade Phillips at the half.

After a safety pulled the 49ers within 28-19, Shaun Phillips made a leaping deflection of a Smith pass at the line of scrimmage and the ball landed right in the mitts of Castillo.

After that, the Chargers got back to their old familiar ways.

"Once we figured out the way they were attacking us," Shaun Phillips said, "We were able to capitalize and do what we do."