In Jake Locker's first career start on Friday night, Tennessee Titans coach Mike Munchak wanted the second-year quarterback to have a commanding presence in the huddle, manage the offense effectively and finish drives in the red zone.

When Locker left the game with 1:48 remaining in the second quarter, the Titans led the Tampa Bay Buccaneers 20-7. Still, it wasn't the performance Munchak had expected from the Titans' 2011 first-round pick. At the 7:23 mark of the second quarter, Locker had completed just 3 of 10 passes for 23 yards and an interception. Locker's QB rating at the time? A Blutarsky-esque 0.0.

Buoyed by a stifling defense that created two turnovers in the red zone, the Titans defeated the Bucs 30-7. Locker, meanwhile, did little to clinch the starting quarterback spot after finishing with 21 passing yards and a QB rating of 7.0.

“It was a little rocky but we found ways to put points on the board,” Locker told WKRN-TV in Nashville. “I thought our running game did really well and our defense put us in some great situations.”

Locker's most glaring error came on a third-down interception in the first quarter from the Titans' 10-yard line. Operating out of the shotgun, Locker stepped up into the pocket and overshot rookie wide receiver Kendall Wright across the middle. The pass was intercepted by Bucs safety Ahmad Black, who returned it to the Titans' 2-yard line. Television footage captured wide receiver Damian Williams and running back Chris Johnson wide open on the play.

Two series later, Locker responded by leading the Titans 71 yards for a touchdown. The drive was capped by a 14-yard run from Johnson along the right end.

“He (Locker) made a bad decision on the one throw trying to make a play in a tough situation, which ended up costing us a touchdown,” Munchak told WKRN. “The good thing was he came back and led the next score for a touchdown.”

Locker and Matt Hasselbeck have struggled in a starting capacity in the preseason. In last week's opener at Seattle, Hasselbeck went 5 of 9 for 45 yards and 2 interceptions. On Friday, Hasselbeck completed 4 of 5 attempts for 29 yards.

Munchak indicated earlier this week that he could make a decision on the starting quarterback several days after an Aug. 23 preseason matchup vs. the Cardinals.

Defense carries the Titans: Although the defense surrendered just 81 total yards, the majority came in the fourth quarter after the game was already decided.

At the end of three quarters, the Bucs had minus-13 passing yards and only 39 yards overall. Tennessee's first- and second-string units recorded four sacks and forced two turnovers. Defensive ends Derrick Morgan and Keyunta Dawson, defensive tackle Sen'Derrick Marks and linebacker Tim Shaw each finished with a sack. The majority of the Titans' pressure came on four-man rushes.

“The defense played so well today, it was fun to watch,” Munchak told WKRN. “The defense (played) awesome, they had a lot of three-and-outs.”

Running backs rack up yardage: Johnson finished with 46 yards on 10 carries and added two touchdowns. It's an encouraging performance for Johnson after his subpar season in 2011.

“It felt good to come out here with my offensive line knowing how hard they work,” Johnson told WKRN. “We have two preseason games left, we have to take a step in each game.”

The All-Pro running back wasn't the only Titans' runner to pound the Bucs on the ground. Tennessee finished with 216 yards on 37 carries, as six different players averaged 4.6 yards per carry or more.

Running back Darius Reynaud rushed for 75 yards on seven carries, exhibiting speed around the edge for the second straight week. Jamie Harper, a second-year running back, displayed power running between the tackles on 9 carries for 41 yards. Fourth-string running back Herb Donaldson added 3 carries for 22 yards.

Harper and Reynaud could earn spots on the 53-man roster if the Titans decide to keep four running backs. The Titans had three running backs on the final 53-man roster in 2011.

For more up-to-the-minute news and analysis on the Tennessee Titans, follow Matt Rybaltowski @CBSSportsNFLTEN.