staggering average of 7.0 yards on a combined 26 carries by Pierre Thomas and Reggie Bush.
In the final 7:51, the Falcons flailed helplessly to stop Thomas, who returned a kickoff 88 yards and ran six times from scrimmage for 29 yards, one touchdown and the game's final first down.
Atlanta's poor defense of Thomas' kickoff return was particularly troubling to Smith.
"There were actually three missed tackles on the kickoff return," Smith said. "There were also a couple of leverage issues where guys were out of position."
He and his staff often chose the wrong time to bring rookie middle linebacker Curtis Lofton to the sideline in favor of an additional cornerback to fill passing lanes against the Saints' NFL-leading air attack.
New Orleans coach Sean Payton used many of those situations to gouge the Falcons for big gains on draw plays. The Saints would line up in a passing formation, causing linebackers Keith Brooking and Michael Boley to adjust their techniques to drop into coverage.
"They had some really big running lanes," Brooking said. "You have to credit Sean Payton with devising a heck of a game plan."
For Lofton, who has emerged as an outstanding defender against the run as a second-round draft pick from Oklahoma, the sight of Bush breaking off a 43-yard run in the first quarter and Thomas twice running for 18 yards in the second was hard to watch.
There was nothing he could do, however, as long as Atlanta defensive coordinator Brian VanGorder was deploying his nickel personnel.
"We lost as a team," Lofton said. "It wasn't one guy's fault or one coach's fault or one group of guys or anything like that. The bottom line is (New Orleans) made the plays they needed to win the game. We just have to get better."
When Tampa Bay visits the Georgia Dome on Sunday, the Falcons (8-5) will have to contend with an arguably more effective and versatile corps of running backs in former teammate Warrick Dunn, Cadillac Williams and Earnest Graham.
The Buccaneers entered their game at Carolina Monday night with the NFL's 11th-best rushing attack.