Updated

Drew Brees had plenty of time to reflect on his missed chances to score as he watched the Tennessee Titans nearly rally past his New Orleans Saints.

The Titans reached the Saints 5 in their near comeback, but Jo-Lonn Dunbar sacked a scrambling Jake Locker as time expired to preserve New Orleans' 22-17 win at Tennessee on Sunday.

"You're sitting there kicking yourself saying, 'Man, it shouldn't have come down to this,'" Brees said. "Jake Locker came back in with a gutty performance, led them down and our defense came up with two big plays on the goal line to get us the victory."

Though New Orleans' top-ranked offense struggled to reach the end zone for three quarters, Brees' two touchdown passes to Marques Colston in the fourth quarter were just enough to help the Saints (10-3) seal their fifth straight victory and stay in control of the NFC South with three games left in the regular season.

They clinched a playoff berth when the Chicago Bears lost in overtime to the Denver Broncos later Sunday.

On third-and-6, Brees threw 35 yards to a wide-open Colston, who fell into the end zone with 12:39 to play. The Saints converted two third downs on their next drive before Brees hit Colston on a 28-yard TD make it 22-10 with 7:01 left.

Colston finished with 105 yards on seven catches. Brees was 36 for 47 for 337 yards and completed passes to nine different Saints.

"It was a gut-check win for us," New Orleans coach Sean Payton said. "A lot of things early on didn't go our way. We had some calls that could have went either way. We just kept fighting and won a good game on the road against a good team."

Tennessee backup Locker threw a 40-yard touchdown pass to Nate Washington to cut New Orleans' lead to 22-17 with 5:58 left. The Titans twice had the ball in the final minutes with a chance to win.

The rookie quarterback entered the game with the score 3-3 with 11:13 left in the second quarter, replacing Matt Hasselbeck, who hurt his left calf trying to chase a tipped pass in the second quarter. Locker was 13 for 29 for 282 yards and a touchdown, and Washington finished with 130 yards on six catches and a score.

Locker hit Washington on an 18-yard pass on second down, and Chris Johnson ran 3 yards around the left end to convert a fourth-and-1 to keep the Titan's second-to-last drive alive.

Faced with another fourth down at the Saints 24 with 2:18 left, Locker kept the ball. Though a replay seemed to show he picked up the needed yard, the officials ruled him down with no gain.

Tennessee (7-6) held New Orleans on the next drive, and Washington caught a 40-yard pass from Locker with 27 seconds left, setting up another chance for a Titans rally.

Locker spiked the ball at the Saints 5 to stop the clock, but his pass on second down to Marc Mariani in the end zone was batted down by Tracy Porter before Dunbar's sack ended the game.

Their loss allowed the Houston Texans, which won at Cincinnati on Sunday, to clinch the AFC South and kept them from gaining any ground in a crowded race for the second AFC wild-card spot.

"As bad as this one's going to hurt ... we can't let this one cost us anymore games," Titans coach Mike Munchak said. "We have three games, we have to win all three games."

Penalties and other mistakes kept New Orleans' league-leading offense from getting any rhythm through three quarters, and three times the Saints got within 11 yards of the end zone only to settle for a field goal. John Kasay kicked field goals of 29, 25 and 22 yards to help the Saints build a 9-3 third-quarter lead.

The Saints also missed another scoring opportunity early in the first half. Darren Sproles returned a punt 82 yards to the end zone, but the score was negated on a holding call on Dunbar.

Notes: Payton and Brees are 20-0 in games where the Saints don't turn the ball over. ... New Orleans improved to 4-3 in road games. ... Klug entered the game leading Tennessee in sacks, and his two against New Orleans gives him six for the season. ... Brees extended his NFL-record streak of games with 20 or more completions to 33. ... The Saints' victory ended a streak of four wins by the Titans in the 13-game series between the teams.