Late in the third quarter, the Saints appeared on course for an easy must-win against a bad Chiefs team. Drew Brees had thrown three TD passes. The maligned defense had limited Kansas City to a pair of field goals. Then the offense went into reverse and Chiefs RB Jamaal Charles revved up. The next thing the Saints knew, they had blown a 24-6 lead and lost 27-24 in overtime, plummeting to 0-3 without suspended coach Sean Payton.

Offense: F

Kansas City came in tied with New Orleans for last in the NFL in points-allowed per game, and the Saints cruised 73 yards for a TD in six plays on their opening possession. But after Brees threw an interception near the goal line late in the third quarter, the Chiefs held the Saints to minus-16 yards on their final four series. That’s right, minus-16. In that span, Brees went 0 for 6, was sacked twice and gave up a safety while the running backs lost two yards on three carries.

Defense: D

Here’s the scary part: The defense played its best game of the year and still gave up 233 yards to Charles, including a momentum-changing 91-yard TD run in the third quarter. Why no failing grade? The Saints got three turnovers after forcing only one in the first two games, and Charles gained only 34 yards on 16 carries after the third quarter. The defense could not make a key stop, but they forced the Chiefs to beat them with four field goals after the third quarter.

Special teams: D

Garrett Hartley’s missed field goal at the end of the half was a forgotten big moment. The snap was fine. The hold was fine. The 38-yard kick was wide right, giving the Saints zero points two plays after a touchdown was reversed on replay review. Thomas Morstead averaged 55.8 points on six punts, but one was returned for 24 yards. The Chiefs stuffed Darren Sproles at the 13 and the 17 when he returned two kickoffs out of the end zone.

Coaching: F

The Saints were rudderless without Payton during the Chiefs’ comeback, which was the largest in Kansas City history. No one on the sideline or the coaches’ booth had any solution for the pass rush that wrecked Brees on the final four possessions as an offense that set an NFL record for first downs got zero. Even worse, total confusion on what defensive players should be on the field after the Saints called a timeout late in regulation led to a delay-of-game penalty when they tried to call a second timeout without a play having been run. The penalty gave the Chiefs a third-and-1 at the New Orleans 30, which the converted easily before a tying field goal with three seconds left.

Follow Saints reporter Guerry Smith on twitter @CBSSaints.