Fitzpatrick completed 12-of-26 passes while Spiller also chipped in with 59 rushing yards on 24 carries for the Bills (6-10), who snapped a three-game losing skid in the season finale for both teams.
The Jets' Mark Sanchez, meanwhile, wrapped up a rough season by managing to complete just 17-of-35 passes, throwing an interception and losing a fumble.
New York (6-10) got 74 rushing yards on 19 carries from Shonn Greene in the setback.
Benedict Cumberbatch's dramatic reading of R. Kelly lyrics is just what you need
Beyonce flaunts bikini body, Blue Ivy in vacation pics