SAN FRANCISCO (AP) — Sure, Reggie Bush felt a bit of sympathy for his former high school quarterback after Alex Smith’s pitiful performance for the 49ers.

Bush felt a whole lot more pride in his New Orleans Saints, who are right back on track after their awful start.

Drew Brees passed for 336 yards and hit Marques Colston with three of his four touchdown throws in the Saints’ 31-10 win over the 49ers on Sunday. New Orleans won its third straight, and San Francisco lost its fifth in a row.

While Smith’s struggles with a still-hurting right shoulder were the most obvious flaws in the 49ers’ effort, few teams could have stayed with the Saints (3-4). The 2006 NFC finalists have rebounded from their 0-4 start to move within one game of the NFC South lead.

Brees was on target, going 31-of-39 and avoiding any sacks for the fourth consecutive game, and Bush added 113 total yards in three quarters.

‘‘We grew up together, and it’s tough to see him struggle like that,’’ said Bush, who took handoffs from Smith at San Diego’s Helix High School. ‘‘But when we’re playing, all bets are off. He’s been a good friend of mine for a long time, and I hope he gets his shoulder back healthy again, but today was all about the Saints.’’

New Orleans jumped to a 24-point halftime lead with a steady offensive effort including catches by nine receivers and four scoring drives longer than 72 yards. With the highest-scoring performance of Colston’s career and Bush’s latest multifaceted game, the Saints were marching again.

‘‘It was fast-paced, and we were very efficient,’’ Brees said. ‘‘I guess we could have been a little better on third down, but it felt like we didn’t have many third downs. Mostly it felt like a lot of first downs. Our defense did a good job, and you just feed off each other.’’

Bush, who had his NFL breakout game with four TDs against the 49ers last year, had 64 yards on 10 carries and added seven catches for 49 yards. Terrance Copper also caught a TD pass, and David Patten had five catches for 109 yards.

After stopping their winless skid with a gritty victory at Seattle, the Saints have fattened up with wins over lowly Atlanta and San Francisco. New Orleans will get a stiffer test next week from a tough Jacksonville squad, but everything seems better for Bush and Brees.

While the Saints got it together, the 49ers (2-5) fell apart. Despite an offseason spending spree, San Francisco has the same record through seven games as last season’s squad, which finished 7-9.

‘‘I just wouldn’t have believed we could start off the way we are with the team we have,’’ defensive tackle Bryant Young said. ‘‘If you would have told me this at the start of the season, I would have called you a liar.’’

Smith and running back Frank Gore both struggled, and the San Francisco defense couldn’t keep the league’s worst offense in it this time. Smith, back in the 49ers’ lineup after separating his shoulder four weeks ago, went 22-of-43 for 190 yards with several noticeably bad throws.

Smith had a painkilling shot before the game and took off his pads once on the sideline for an examination. The third-year quarterback refused to come out, but couldn’t get anything going until late.

‘‘Coming back after four weeks, the throwing arm felt not quite accurate in the first half,’’ said Smith, whose postgame X-rays revealed nothing new. ‘‘Once I taped my collarbone down, I felt better. I was determined to stay in there.’’

Gore twisted his ankle again in the second half, finishing with just 41 yards rushing. San Francisco needed an 80-yard drive with the game already decided to surpass 200 yards of offense for just the third time all season.

Brees found Colston uncovered for the Saints’ first score just 3:37 in. Copper’s 2-yard TD catch capped a 91-yard drive midway through the second quarter, putting New Orleans up 17-0.

Colston, who had just eight catches in the last three games, caught a 3-yard TD pass 50 seconds before halftime. He made his prettiest play in the fourth quarter, leaping to get the ball and dragging his feet in the final inches of the end zone.

‘‘With the talent we have at receiver, you never know whose day it’s going to be,’’ Colston said. ‘‘It was good to go out and score quick, and get our swagger back.’’