ST. LOUIS — The St. Louis Rams made one more mistake than they could overcome.
A fumble by quarterback Kellen Clemens led to Chris Johnson's 19-yard touchdown run with 2:54 left in the fourth quarter, carrying the Tennessee Titans past the Rams 28-21 on Sunday at the Edward Jones Dome.
Clemens fumbled as he was being sacked by Titans defensive tackle Jurrell Casey. The ball was recovered by defensive end Derrick Morgan at the St. Louis 19.
"They got a little bit of penetration, so I tried to step up and their big D-tackle just knocked the ball out," Clemens said. "Unfortunately, I put our defense in a very difficult situation. It's a mistake that can't be made, and unfortunately I made it."
On the next play, Johnson ran for his second touchdown of the game to help the Titans (4-4) snap a three-game losing streak.
"We turned it over twice, we turned it over twice to a good running football like that, it's hard to win," Rams coach Jeff Fisher said.
Fisher watched as his defense was bludgeoned for 198 rushing yards by the Titans, who he coached for 17 seasons before coming to the Rams.
Johnson had 23 carries for 150 yards and his first two rushing touchdowns of the season.
"We lost the edges," Fisher said. "When C.J. gets on the edge, he goes. We emphasized it all week."
It was a major step back for a run defense that limited the Seattle Seahawks to 44 rushing yards in a 14-9 loss just six days earlier.
"The offense did a great job trying to keep us in it, but we can't be one team one week and another team another week," Rams defensive end Chris Long said. "It's very, very disappointing."
The loss was third in a row for the Rams (3-6), who moved the ball to the Tennessee 26 before having their comeback bid end with two incomplete passes to Austin Pettis.
On the first pass, it looked like the Titans' defensive back could have been called for pass interference.
"I think possibly, but that's his job to do whatever he can to stop me from catching the ball," Pettis said.
Zac Stacy had 27 carries for 127 yards and the Rams' first two rushing touchdowns of the season.
Clemens completed 20 of 35 passes for 210 yards and one touchdown. His quarterback rating was 84.2.
The Titans marched 68 yards on seven plays for a touchdown on the opening drive of the game.
Three consecutive penalties on the Rams -- defensive holding against Cortland Finnegan, a horse-collar tackle by Darian Stewart and illegal use of the hands by Jermelle Cudjo-- enabled the Titans to move the ball from the St. Louis 33 to the 5-yard line.
Shonn Greene scored on a 5-yard run with 11:53 left in the first quarter.
The Rams drove the ball deep into Tennessee territory on their first possession, but Benny Cunningham fumbled the ball into the arms of Titans cornerback Coty Sensabaugh at the Tennessee 10.
But they still did tie it at 7-7 by putting together a 12-play, 80-yard drive that was capped by a 3-yard touchdown run by Stacy.
Finnegan stepped in front of a pass intended for Kenny Britt for an interception at the Tennessee 26 late in the first half.
The Rams were unable to capitalize on the takeaway as Greg Zuerlein was wide right on a 44-yard field-goal attempt with 26 seconds left in the first half.
But they did take a 14-7 lead with a 10-play, 80-yard touchdown drive to open the second half.
Stacy scored on a 9-yard touchdown run to complete the drive.
The Titans answered with a 70-yard drive. Johnson ran 14 yards for a touchdown to knot the score at 14-14.
Locker scrambled 5 yards up the middle for a touchdown with 9:42 left in the fourth quarter.
A 10-yard touchdown pass from Clemens to tight end Jared Cook tied it at 21-21 with 6:15 to go.
Contact reporter Steve Korte at firstname.lastname@example.org or 239-2522.