After starter Matt Hasselbeck threw 10 passes and completed four of them, Whitehurst came on to go 14-of-22 for 214 yards.
Whitehurst gave Seattle a 10-7 halftime lead with a 51-yard scoring pass to Mike Williams midway through the second period. He then hit Anthony McCoy with a 4-yarder in the closing seconds of the third period for a 20-7 advantage.
The Titans staged a fourth-quarter comeback bid, with Rob Bironas kicking a 47-yard field goal and LeGarrette Blount scoring on a 1-yard run, after which the Titans were good on a two-point conversion pass from Rusty Smith to Marc Mariani.
Tennessee's Vince Young hit five of the six passes he attempted, but was intercepted once. He drove the Titans 78 yards in nine plays to a touchdown in the first period -- that coming on a 1-yard run by Chris Johnson.