Saints cornerback Corey White celebrates his interception with free safety Isa Abdul-Quddus in the second half against the Atlanta Falcons. The turnover led to a touchdown. (AP)

The Saints needed to play their best game of the year to beat the undefeated Falcons, and that’s exactly what they did. Drew Brees was Drew Brees. They gashed the Falcons on the ground in the first half. They stopped the run, and the defense made plays against the pass when it was absolutely necessary.

New Orleans (4-5) is far from perfect after nine games, but the playoffs remain a possibility despite their dreadful 0-4 start. A loss to Atlanta would have pretty much ended those hopes.

Offense: A-

The Falcons had not given up more than 28 points in a game and had held their last four opponents to 20 or fewer, but the Saints had their way after a Brees interception on their first offensive play. Running back Chris Ivory scored on a 56-yard run to spark a stretch of four TDs in six possessions. Brees was efficient (21 of 32 for 298 yards and three TDs) and spectacular when he needed to be. Tight end Jimmy Graham, finally healthy after being slowed by an ankle sprain, had a career-high 146 receiving yards on seven catches. Right tackle Charles Brown started and filled in nicely for the injured Zach Strief -- Brees was sacked only once. A couple of quibbles: Graham dropped a third-down pass, and the running game produced only 32 yards on 16 carries in the second half after a big first half. Last week’s grade: B

Defense: B

Atlanta’s Matt Ryan threw for a career-high 411 yards, but he needed 52 passes to do it. For the first time all year, the Saints held an opponent to fewer than 100 yards rushing, and the Falcons did not even come close. Michael Turner had 15 yards on 13 carries. The Saints gave up some big passes, but as interim coach Joe Vitt pointed out, the Falcons are loaded at the skill positions with Ryan throwing to tight end Tony Gonzalez and big, fast receivers Julio Jones and Roddy White. New Orleans came up huge in short-yardage situations, stuffing Turner on third and 1 to force an early field goal, pressuring Ryan into a bad throw on third and 1 to force a punt the next time the Falcons had the ball, and stopping the Falcons on three straight plays from the 1 and 2 to take over on downs at the end of the game. Last week’s grade: B

Special teams: A

As defensive coordinator Steve Spagnuolo pointed out Monday, maybe the biggest play of the game was Thomas Morstead’s booming 55-yard punt from the New Orleans 4 in the final minute. The Falcons had no return and lost another 10 yards on a holding call, giving them the ball at their 31 with 37 seconds left. That’s the norm for Morstead, an All-Pro caliber punter. He averaged 50 yards on his five punts, and he also had touchbacks on all six of his kickoffs. Garrett Hartley made his only field goal attempt, from 31 yards. Last week’s grade: C

Coaching: A

Playing a confident, undefeated team, the Saints won a game they absolutely had to have. Vitt is 2-1 since returning from his suspension, and the staff deserves tremendous credit for holding the team together after an 0-4 start and then an ugly loss to Denver that dropped the Saints to 2-5. On offense, they finally have unleashed Ivory after mistakenly not using him in the first seven games. On defense, they are playing more aggressively as they get more comfortable in Spagnuolo’s scheme. No one panicked even though the Saints are on pace to shatter the NFL record for most yards allowed in a season. That calmness is starting to pay off. Even without Sean Payton, the Saints' mastery of the Falcons under Mike Smith continued. He is now 2-7 against them. Last week’s grade: B+

Follow Saints reporter Guerry Smith on Twitter @CBSSaints.