Locker, the eighth overall pick in the 2011 draft, spelled starter Matt Hasselbeck after Tennessee's first series and completed 7-of-10 passes for 89 yards.
In the second quarter, Locker fumbled a snap, but recovered the ball and found Yamon Figurs for a 45-yard touchdown.
Hasselbeck, who was signed by the Titans after leaving the Seahawks during a frenzied offseason, completed 5-of-6 passes for 55 yards in his one series before the drive stalled.
Jamie Harper, starting in place of holdout Chris Johnson, ran for 27 yards and a score. Harper was selected in the fourth round of the 2011 draft.
Donovan McNabb, acquired from Washington after the lockout, played two series, both of which resulted in punts. He threw for 40 yards, completing 6-of-11 passes.
Christian Ponder, the Vikings' 12th overall draft pick, entered the game midway through the third quarter. The Florida State product went 8-for-13 for 84 yards.
Minnesota opened the second half with an 11-play, 59-yard drive, which resulted in a 37-yard field goal by Ryan Longwell. The drive was orchestrated by Joe Webb, who threw for 45 yards on 4-of-8 passing.