It looked bleak for the Titans in the final stages of the fourth quarter. Thanks in large part to running back Chris Johnson, bleak went to bright in an instant. Johnson busted loose for a 19-yard touchdown run with 2:54 remaining to lift the Titans to a 28-21 win over the Rams here on Sunday. In his best game of the season, Johnson rushed for 150 yards and two touchdowns on 23 carries. The touchdowns were his first rushing scores of the season. With the game tied 21-21, the Rams had the ball with a chance to take control. But defensive tackle Jurrell Casey sacked Rams quarterback Kellen Clemens and forced a fumble that defensive end Derrick Morgan recovered. Johnson scored on the next play and the Titans (4-4) survived a last-gasp drive from the Rams (4-6) and former Titans coach Jeff Fisher. Rams running back Zac Stacy, a former Vanderbilt star, rushed for 127 yards and two touchdowns on 27 carries. The visitors overcame a pair of interceptions from quarterback Jake Locker, who was 13-of-22 passing for 185 yards in his second game back from knee and hip injuries. The Titans took the opening kickoff and went 68 yards on seven plays, capping the drive with Shonn Green’s five-yard touchdown run. The Rams answered in the second quarter with a time-consuming drive, as Stacy scored on a three-yard run to end a 12-play, 80-yard drive that took 8:05 off the clock. The game was tied at 7-7 at the half.