San Diego ? Backup quarterback Billy Volek threw a two-point conversion pass to Malcom Floyd in the fourth quarter, giving the San Diego Chargers an 18-17 preseason victory over the Seattle Seahawks on Monday night.

Volek’s lob to Floyd followed a one-yard touchdown run by rookie Jacob Hester that pulled the Chargers within 17-16 with 2:30 left in the game. The 6-foot-5 Floyd out-jumped Omare Lowe, a 6-1 cornerback, near the left sideline in the end zone for the go-ahead score.

Both teams played their starters for most of three quarters and likely will rest them in their final preseason games Friday.

Philip Rivers completed 11 of 21 passes for 143 yards, driving the Chargers to the one-yard line on their first possession before a bad snap out of the shotgun formation by backup center Jeremy Newberry was recovered by Seattle.

Two-time rushing champion LaDainian Tomlinson was again out of the lineup for the Chargers, but Darren Sproles filled in with 102 yards on 13 carries, including a one-yard TD run.

San Diego (2-1) overcame a fine performance by Seattle’s Charlie Frye, who threw two touchdown passes starting in place of Pro Bowler Matt Hasselbeck. The Seahawks’ third-stringer completed 19 of 30 passes for 219 yards, with touchdown passes to Nate Burleson and Jordan Kent.

Hasselbeck, who did not make the trip, also missed last week’s game against Chicago due to a tight back. Seahawks coach Mike Holmgren has indicated that Hasselbeck probably will not play until Seattle’s season-opener at Buffalo on Sept. 7.