NEW ORLEANS — Early in the fourth quarter of Sunday night’s game with the Detroit Lions, the New Orleans Saints’ offense decided that enough was enough.

For the first 17? minutes of the second half, the Saints were little more than innocent bystanders as they watched the Lions play a game of keep-away with the NFL’s top-ranked offense.

But after trimming a 24-7 halftime deficit to seven points with a field goal and touchdown in the third period, Lions coach Jim Schwartz made a tactical error in putting the ball in Drew Brees’ hands with a short field to work with.

Brees made Schwartz pay dearly when he drove his team 55 yards in seven plays to the touchdown that gave them a more-comfortable advantage en route to a 31-17 victory in the Mercedes-Benz Superdome.

The turning point came when the Lions were facing a fourth-and-12 at the Saints’ 37. Instead of sending in the punt team, Schwartz called on Jason Hanson to try a 55-yard field goal that was wide left.

That gave the Saints the ball at their 45, the spot of the missed field goal.

“You weigh your options,” Brees said of Schwartz’s decision. “If you make it, it’s big-time and a big momentum swing in their favor. If you miss it, it’s great field position.”

From there, Brees was 5-of-6 for 52 yards on the drive. He connected with tight end Jimmy Graham, who became the first tight end in Saints’ history to have a 1,000-yard receiving season, four times for 46 yards on the march.

Then, Brees, who hit on 26 of 36 passes for 342 yards and went over the 4,000-yard mark for the sixth consecutive season, threw his third touchdown of the night when he hit wide-open running back Darren Sproles for a 6-yard score with 9:44 left to make it a 14-point game.

“They scored 10 quick points to start that second half and all of a sudden we find ourselves in the fourth quarter,” said Brees, who tied an NFL record by going over the 4,000-yard mark in passing for the sixth straight season on that key drive. “We haven’t scored, and we haven’t helped our defense.

“There was a sense of urgency, especially after they missed that long field goal, to go down and pad the score and help the defense.”

“In the third quarter, the momentum shifted, and I thought it would be important for us to answer,” Saints coach Sean Payton said. “I like the fact that we’re playing with confidence, and I like the fact that we answered when that momentum shifted.”

The Saints (9-3) won for the fourth straight time and extended their lead in the NFC South standings to two full games over the Atlanta Falcons with four regular-season games remaining.

The Saints started the day with a one-game lead over the Falcons, who dropped a 17-10 decision to the Houston Texans earlier Sunday, and then moved closer to clinching a third straight playoff berth with the victory over the Lions (7-5).

It wasn’t as easy as it looked early as the Lions, who won an NFL-record four games earlier this season after trailing by at least 17 points, tried to come all the way back again.

After taking a 3-0 lead in the first quarter on a 39-yard John Kasay field goal, the Saints got a 14-yard touchdown run from Mark Ingram and a 67-yard scoring strike from Brees to Robert Meachem for a 17-0 lead with 8:03 to play in the second period.

After the Lions got into the game with an 80-yard drive that was capped by a 2-yard TD run by Kevin Smith with 2:28 to play before halftime, Brees took his team 80 yards and got the final 20 yards on a pass to Lance Moore for a 24-7 lead with 22 seconds left.

The Lions managed to get back into field goal range, but Hanson’s 42-yard field goal on the final play of the half was partially blocked by Saints cornerback Patrick Robinson.

But despite being denied there, they were not deterred.

They started the second half with a 10-play, 67-yard drive that resulted in a 31-yard field goal by Hanson that made it 24-10.

After stopping the Saints, the Lions shocked the crowd with a nine-play, 88-yard drive that was capped with a 9-yard TD pass from Matthew Stafford to tight end Tony Scheffler with 43 seconds to play in the third period.

They got the ball back after forcing the Saints into a three-and-out and mounted another impressive drive to reached the New Orleans 35 with a first down.

The Saints defense stiffened at that point, however, dropping running back Maurice Morris for a 2-yard loss and then forcing Stafford into two straight incompletions — which prompted Schwartz to send out Hanson for the 55-yard field goal that drifted wide of the left upright.

That brought out Brees and his offense, which had just seven snaps in the third quarter and nine in the second half when they got the ball back with 12:38 left.

“On that drive, you never know who’s going to get those balls,” Brees said. “Jimmy caught quite a few of them. One was on a checkdown when I was looking for Devery (Henderson) and Marques (Colston). But there was Jimmy all alone for the reception, and we got another first down.”

“Drew just said, ‘One drive, one play at a time,’ ” said Graham, who caught eight passes for 89 yards. “That’s what we focused on — converting third downs and marching down the field.

“We did that and wound up scoring there. That was a great drive by Drew, he’s a surgeon out there.”