Brown lined up to try a 45-yarder that would have forced overtime, but guard Louis Vasquez was whistled for a false start. Moved back five yards, Brown's attempt was long enough but bounced off the right upright. Brown was signed last week because Nate Kaeding has an injured groin.
Leading by three with two minutes left, New England gambled on fourth-and-1 from its 49 and BenJarvus Green-Ellis was stuffed for a 1-yard loss by Antwan Applewhite. Coach Bill Belichick had challenged the spot of the previous play and lost, costing him his final timeout. San Diego then moved to the 27.
New England (5-1) pulled into a tie with the idle New York Jets atop the AFC East. The Chargers fell to 2-5.