Freeman's scoring strike to Winslow came with 3:47 left in the game. It gave the Bucs a 15-10 lead, and Freeman rushed into the end zone for a crucial 2-point conversion to make it 17-10.
Donovan McNabb found Santana Moss up the middle for 9-yard TD pass with 9 seconds left to pull Washington to within a point, but the Redskins botched the snap on the ensuing extra point try and Tampa Bay hung on for the win.
Freeman threw for 266 yards, connecting on 15-of-25 passes, Connor Barth went 3-for-3 on field goal attempts and LeGarrette Blount gained 68 yards on 15 carries for Tampa Bay (8-5), which broke a two-game losing streak.
McNabb tossed for 227 yards, completing 22-of-35 pass attempts with two scores for Washington (5-8).