The Chargers entered the game 2-0 at home and nearly pulled it out in the end after scoring 14 unanswered points in the fourth quarter, but the Patriots held on when Kris Brown missed a game-tying field-goal attempt in the closing seconds.
"Tough place to play, good football team," Patriots coach Bill Belichick said. "(The) Chargers do a lot of things well. They've got a lot of talent. Always a tough place to play, and (there have) been a lot of hard-fought games out there.
"Good to come up with a few more plays than San Diego did (Sunday and) come out on top. A lot of big plays in the game that affected it, or had they gone a little bit differently, things might've been different either in their favor or maybe more in our favor. I don't know, but in any case, it came down to a couple plays there at the end."
San Diego had a chance after stuffing the Patriots on fourth-and-1 in its own territory, but it failed to get close enough to make Brown's field-goal attempt manageable. His first shot at a 45-yarder was negated by a false start penalty, pushing him back five additional yards.
The Patriots are proud of the win, which improved their record to 5-1, but they're also cognizant of some of their missed opportunities, which might have added more separation between the teams.
"We missed opportunities in all three phases of the game — missed them on offense with good field position," Belichick said. "We had a couple of plays where we could've really ended drives — third down, fourth down — (and in the) kicking game, missed opportunities there.
"Start off the game with a penalty. Had four penalties on special teams in the first half. Certainly, a lot of room for improvement, no question about it. We could've done just about everything better at some point or another."
Mayo became the first Patriots player to finish three consecutive games with 10 or more tackles since Tedy Bruschi went three straight games with 10-plus tackles in 2006.
Mayo had 17 tackles at Miami on Oct. 4 and 19 against Baltimore two weeks later. Sunday was his fourth game in 2010 with 10 or more tackles; he also had 11 in the opener against Cincinnati.
The Patriots' best records through six games under Belichick are 6-0 in 2004, 5-1 in 2006 and 6-0 in 2007.
He has caught at least one pass in each of his 55 games with the Patriots, including three postseason games. The last time that Welker did not catch a pass in a game was Dec. 24, 2005, when he was with the Dolphins.