"This hurts quite a bit because we were looking forward to playing, basically, probably the top team in the NFC," Rams wide receiver Brandon Gibson said. "So it hurt a little bit because we didn't play to the best of our ability, but we learn from our mistakes and come back and look to next week and get a win."
The Rams (4-6), who had a four-game home win streak snapped, held a 17-16 lead for most of the third quarter after Gibson caught a 13-yard touchdown pass from rookie quarterback Sam Bradford.
The visitors from the NFC South were on the ropes and the crowd of 53,005 at the Edward Jones Dome was fired up and making noise.
But then the Falcons (8-2) showed why they are one of the best teams in the NFL when they responded for 17 unanswered points and safety William Moore swung momentum in Atlanta's favor when he grabbed an game-changing interception to prevent a possible Rams score.
"It's tough," Rams defensive end Chris Long said. "They're a good ballclub. We had our chances to make some big plays on defense and we gave up some big plays conversely. You can't make mistakes against a good team like that. They ended up burning us."
The Falcons finished with 391 total yards, did not turn the ball over and did not allow a sack. Kicker Matt Bryant made four field goal attempts, with three in the first half and a 21-yarder with 7 minutes and 57 seconds remaining that gave Atlanta a 26-17 lead.
"They do everything really well," Rams coach Steve Spagnuolo said. "They're really solid, they're well-coached, they've got a great system, they've got really good players. Yeah, they're good."
"They really don't have any weaknesses in their offense," Rams safety Oshiomogho Atogwe said. "They are able to attack in all facets and it would present any defense with a challenge. I felt we played with them pretty well, fairly well, for the most part of the game. They just outplayed us."
Wide receiver Roddy White kept the chains moving with nine catches for 83 yards. Running back Michael Turner racked up 131 rushing yards on 28 carries, including a 39-yard touchdown run with 1:52 seconds left that served to eliminate any hope of a St. Louis comeback.
"They're definitely a good offense," Rams middle linebacker James Laurinaitis said. "We knew that coming in. They have a lot of weapons. They have a good quarterback. They have a great quarterback. We knew that. I think we definitely hurt ourselves on some plays. We had some missed tackles. We had some just blown assignments and stuff like that."
The Rams had 304 total yards. Bradford completed 27 of 42 passes for 233 yards, with two touchdowns and one interception — which snapped his NFL rookie record of 169 consecutive passes without an interception.
That play, the interception by Moore, came with 3:24 left in the game and St. Louis trailing 26-17. Bradford was trying to hit rookie tight end Michael Hoomanawanui — who caught a 25-yard touchdown pass in the first quarter — on a shovel pass down near the goal line.
"That's kind of a tough play," Bradford said. "I let it go without really finding my receiver, which is something I really can't do/ I got to make sure it's there. If not, I probably should have just pitched it to the ground and got us the fourth down where we could have either gone for it or kicked a field goal."
The No. 1 overall pick admitted that the turnover hurt.
"That's going to stick with me for a while," he said, "but got to move on."
Rams running back Steven Jackson rushed for 54 yards on 11 carries. Wide receiver Danny Amendola finished with a team-high eight catches for 63 yards, while Laurent Robinson had five catches for 55 yards and Gibson added five catches for 42 yards and a touchdown.
St. Louis now goes on the road for three weeks with games at Denver, Arizona and New Orleans. The Rams are 0-4 on the road this season.
"We're just going to worry about this game coming up," Spagnuolo said. "Well, I'm going to worry about today right now and how we played, and then probably still be on that tomorrow after we get through the film, and then we'll worry about Denver, where we play them."