"The turnovers (are) what ended up killing us," Titans coach Mike Munchak said.
Locker also was sacked six times, and the Titans (4-8) lost their second straight along with right tackle David Stewart breaking his right leg on the opening series. Left guard Steve Hutchinson also hurt his right knee late in the first half, and even left tackle Michael Roos went out briefly after going down.
That left Locker getting banged around and knocked down to the point he even bit his tongue on a play that had coaches worried the quarterback hurt his left, non-throwing shoulder again.
Munchak fired offensive coordinator Chris Palmer on Monday, hoping to provide a boost to the offense. Tennessee outgained Houston (11-1) 354-332 in total offense. But once Locker settled down after a rough start that saw him throw incomplete on seven straight passes in the first quarter, he got little help as teammates dropped a handful of balls.
"The players eventually have to catch those balls, make plays, and we didn't at times," Munchak said.
While the Titans figure out what to play for next, the Texans enjoyed clinching a second straight postseason berth and setting a franchise record for wins in a season.
"We're very happy, I can tell you that," Texans coach Gary Kubiak said. "But I think they expected to get there, and they got there today. There's a lot more to work on. We've got to continue to push our group."
Rookie linebacker Whitney Mercilus recovered a fumble and had two sacks as the Texans remain tied with Atlanta for the best record in the NFL with their sixth straight win. The Texans turned those turnovers into 10 points and also improved to 6-0 on the road this season, the only unbeaten team away from home.
The Texans also swept Tennessee, the team they replaced in Houston, for only the second time. Matt Schaub threw for 207 yards and two touchdowns, and Arian Foster ran for a TD.
"To work so hard to turn things around and go out and have a performance like that is very frustrating," Titans running back Chris Johnson said.
Tennessee scored on a 34-yard pass from Locker to Kenny Britt late in the third quarter to pull within 24-10. The Titans had plenty of chances, including third-and-3 at the Houston 7 early in the fourth quarter before Locker was sacked and fumbled on fourth down.
Darryl Sharpton sealed the win with the third interception with 2:05 left. Locker finished with two fumbles and three interceptions.
"I guess that's why we're 4-8," Munchak said. "We can't make enough plays to win when we have an opportunity."
The Texans avoided all the late-game dramatics needed in beating first Jacksonville, then Detroit in overtime in a span of five days. But their injury list grew a bit longer when cornerback Brice McCain hurt his foot and couldn't finish. Tight end Garrett Graham also suffered a head injury and couldn't finish.
Houston improved on last season's 10 wins with Schaub tossing a TD pass each to Lestar Jean and James Casey for a 14-3 lead in the second quarter. By halftime, Schaub completed passes to eight teammates, including himself off a batted ball he pulled in for a 6-yard loss.
Shaun Cody tipped Locker's pass to Houston linebacker Tim Dobbins, a Nashville native, who ran it 7 yards to the Tennessee 3 before Locker knocked him up into the air. Arian Foster scored on a 2-yard TD run two plays later for a 21-3 lead midway through the second quarter. Shayne Graham added a 50-yard field goal in the third quarter after Mercilus recovered Locker's fumble forced by Antonio Smith.
That was all Houston needed with the defense disrupting Tennessee repeatedly.
Texans defensive end J.J. Watt had another sack, giving him 15 1-2, adding to his franchise record for a season and joining Reggie White as the only NFL players with at least 15 sacks and 13 passes defensed in a season. Watt batted down a couple of passes, giving him 15 for the season.
"Obviously, we've had some struggles the last two weeks, but today is what we're used to and the way we're used to playing with the turnovers and the momentum swings," Watt said.
Smith had a sack and recovered a fumble by Johnson he ran to the end zone waving the ball in the air, thinking and hoping he had a TD in the second quarter.
But officials had whistled the play dead at the spot of the turnover.
Notes: Andre Johnson, the AFC offensive player for November, had five catches for 56 yards after totaling 35 catches for 614 yards over the past month. ... Foster's streak of rushing for at least 90 yards a game ended at five. He ran for 38 yards on 14 carries.
Houston 14 7 3 024
Tennessee 3 0 7 010
Hou_Jean 54 pass from Schaub (S.Graham kick), 12:29.
Ten_FG Bironas 37, 9:30.
Hou_Casey 5 pass from Schaub (S.Graham kick), :19.
Hou_Foster 2 run (S.Graham kick), 7:48.
Hou_FG S.Graham 50, 6:54.
Ten_Britt 34 pass from Locker (Bironas kick), 1:34.
First downs 16 17
Total Net Yards 332 354
Rushes-yards 35-125 17-89
Passing 207 265
Punt Returns 4-67 6-65
Kickoff Returns 1-14 2-56
Interceptions Ret. 3-27 0-0
Comp-Att-Int 21-35-0 21-45-3
Sacked-Yards Lost 0-0 6-44
Punts 10-48.8 6-50.5
Fumbles-Lost 1-0 3-3
Penalties-Yards 11-97 4-35
Time of Possession 33:48 26:12
RUSHING_Houston, Forsett 14-64, Foster 14-38, Tate 3-18, Schaub 4-5. Tennessee, C.Johnson 13-51, Locker 4-38.
PASSING_Houston, Schaub 21-35-0-207. Tennessee, Locker 21-45-3-309.
RECEIVING_Houston, Johnson 5-56, Foster 5-15, Walter 4-33, Daniels 3-43, Jean 1-54, G.Graham 1-7, Casey 1-5, Schaub 1-(minus 6). Tennessee, Wright 6-78, Cook 4-51, C.Johnson 4-20, Washington 3-96, Britt 2-40, Williams 2-24.
MISSED FIELD GOALS_None.