The Lions (8-5) kept their playoff hopes alive with the victory, snapping a two-game slide.
They built a 31-14 halftime lead when Tulloch recovered a fumble in the end zone only 2 minutes into the game and Smith returned an interception for a score in the second quarter.
But Minnesota then reeled off 14 of the next 17 points and it came down to the game's final play.
Vikings quarterback Joe Webb fumbled with Minnesota only one yard away from the winning score, and Cliff Avril -- whose rush had hurried Webb -- came up with the recovery as time expired.
Webb completed 12-of-23 passes for 84 yards after replacing the ineffective Christian Ponder for Minnesota (2-11), which lost its fifth straight.