Too late to make a difference, Drew Brees completed a short toss over the middle in the closing seconds that preserved his remarkable touchdown streak.
It was his pass toward the right sideline moments earlier for a TD _ a Rams TD, that is _ that finished a lost afternoon for the New Orleans Saints.
Coming off a record rout, and prohibitive favorites to romp again, Brees and the Saints fizzled Sunday in a 31-21 loss to backup quarterback A.J. Feeley and winless St. Louis.
"As you look at the cardinal sins of football, we committed quite a few of those today," Brees said. "Obviously, we gave them a lot of momentum."
On a day when Chris Carpenter, Tony La Russa and about a dozen members of the World Series champion St. Louis Cardinals were saluted on the field, the Saints (5-3) hardly showed championship form.
More startling: The NFC South leaders fell flat a week after Brees threw five touchdown passes in a 62-7 demolition of Indianapolis that matched the highest point total since the AFL-NFL merger in 1970.
"Obviously, it's a disappointing loss. They outplayed us today, it was clear," said Saints coach Sean Payton, who worked from an upstairs box with a knee injury that's left him on crutches. "I just thought we looked flat."
Or, as he said he told his team: "Everyone in there, starting with me, has got to be better."
The NFL's top-scoring team trailed 24-14 when Brees came on the field with 3:01 left. On first down from his own 20, Brees tried to hit right end Jimmy Graham. Instead, safety Darian Stewart made a tumbling interception, rolled over and headed toward the end zone.
Brees bumped Stewart just before the goal line, to no avail on a 27-yard TD return with 2:51 remaining. As the Rams (1-6) celebrated, Saints guard Jahri Edwards drew a penalty for kicking the ball into the stands.
Brees came back to throw a TD pass with 6 seconds left to Lance Moore. That marked the 35th straight game for Brees with a touchdown pass _ the only longer strings are 47 games by Johnny Unitas and 36 by Brett Favre.
"I could care less, to be honest," Brees said. "That stuff comes when you win, and it means more when you win."
He did, however, see some positive in that late score. It showed, he said, "we're never going to quit."
There was a report on the Saints' radio network that guard Carl Nicks and offensive line coach Aaron Kromer argued late in the game and needed to be separated. Brees brushed aside any details.
"We got guys that are passionate about the game and want to win. There's obviously some fiery moments all the time. I'm not worried about anybody turning on anybody. That's not our team," the quarterback said.
Brees finished 30 of 44 for 269 yards. The Saints faced a lot of third-and-long situations and rarely converted. In fact, Payton said, they were sometimes at a loss over what to call.
"We almost ran out of plays," he said.
The game began to spiral out of control late in the first half. Ahead by a field goal, the Rams quickly capitalized on a pair of turnovers to go up 17-0 at the break.
Steven Jackson scored on a 3-yard run two plays after rookie Robert Quinn's blocked punt, the first in three NFL seasons against Thomas Morstead. Then Josh Gordy's interception at the Saints 38 gave St. Louis another short field that led to Feeley's 8-yard TD pass to Brandon Lloyd.
The Rams had faced double-digit deficits at halftime in every previous game this season. The Saints, meanwhile, had not been blanked in a first half since early in the 2007 season.
Jackson wound up running for 159 yards on 25 carries, including a 32-yard jaunt on fourth-and-2 to set up his second touchdown that made it 24-0 in the third quarter.
Bottled up, the Saints didn't score until Jonathan Vilma recovered Feeley's fumble on a sack by Malcolm Jenkins for a touchdown with 1:21 left in third period. Pierre Thomas scored on a 3-yard burst with 10 minutes left to cut the gap to 10.
The Saints never got closer, and the Rams finished off a win soon before the Cardinals were about to start their victory parade.
The excitement over the Cardinals certainly fired up the crowd. Whether it inspired the Rams, well, Payton dismissed that.
"I think we're reaching with baseball," he said. "I don't think so. Look, I know this city is extremely excited about their baseball championship, but I don't think that carries over to the game today."
Rather, the Saints never got on track against a defense ranked near the bottom of the league. The Rams had a season-high six sacks after entering the game with just 11, three by Chris Long.
"We always thought we had that in us," coach Steve Spagnuolo said. "It was a wonderful weekend for St. Louis fans."
Notes: Mark Ingram, the Saints' leading rusher, did not play after missing all week with an injured right heel. Chris Ivory came off the physically unable to perform list and ran for 18 yards on six carries. Thomas ran for a team-high 23 yards in seven tries.