Four of the Ravens' seven turnovers led to 20 points as they bowed to the Rams in a wild 33-22 loss before 66,085 at Edward Jones Dome and a national television audience.
The miscues ruined a dominating effort by the Ravens' defense, which held the Rams to a season-low 121 yards of total offense. At one point, the Ravens kept the NFL's top-ranked offense without a first down on seven straight series.
But the Ravens' sloppiness lost them more than a two-game lead in the AFC North. Rookie quarterback Kyle Boller sprained his left knee in an accidental collision and did not play the second half. His status will be evaluated today when he undergoes a magnetic resonance imaging test in Baltimore.
With or without Boller, the story line remained the same for the Ravens, who tied a team record by turning the ball over seven times. With four by the Rams, the 11 total turnovers were a high for an NFL game this season.
"It's very disappointing to lose like that with the mistakes," coach Brian Billick said. "I thought the team showed incredible resiliency on the road through all the things we made happen and didn't make happen. We'll come back and fight through it."
The Ravens (5-4) remain in first place in the AFC North but saw their lead dwindle to one game over the Cincinnati Bengals. The Rams (6-3) won their 11th straight game at home, the longest streak in the NFL.
The tone was set on the first drive that featured 20- and 23-yard runs by Jamal Lewis and ended with an interception by Boller. The entire night was a series of one step forward and one stumble back.
Boller finished with one interception and a fumble, both of which were converted into touchdowns. Seeing his first extensive action this season, backup quarterback Chris Redman threw two interceptions, fumbled once and was sacked five times.
Even the offense's foundation, Jamal Lewis, cracked at critical times. The NFL's leading rusher had 111 yards on 27 carries for his seventh 100-yard game, but he also lost two fumbles.
One came deep in Rams territory and another led to Jeff Wilkins' 48-yard field goal that put the Rams ahead 30-22 with 5:25 to play. It marked the first fumbles Lewis had lost since the season opener.
"He can't do it and he knows that," Billick said. "He will do everything not to do it again."
To make matters worse, a Ravens offense that re-established its rhythm in the red zone near the end of the first half - which included a 1-yard toss to offensive tackle Jonathan Ogden - was thrown off-course when Boller was sidelined after halftime. The first-round pick banged knees with fullback Alan Ricard with 3 1/2 minutes left in the second quarter.
Boller, who was 10-for-21 for 112 yards, played out the rest of the quarter but his left knee stiffened during halftime.
"I'm definitely worried," Boller said. "Any time you get an injury like this, especially with a knee, you want to make sure it's going to be all right."
Redman looked like a quarterback who had thrown just one pass this season. He was 7-for-12 for 58 yards.
"Obviously, I struggled and turned the ball over too many times," Redman said. "I have to keep fighting and push through it and put it behind me. It was a rough start, but you can't find any excuses. You have to keep moving on."
Despite the haphazard quarterback change, the Ravens took their first lead of the game early in the third quarter, when Chester Taylor forced Rams punt returner DeJuan Groce to fumble at the St. Louis 28. In what was a sign to come, the Ravens sputtered with the prime opportunity but still went ahead 22-21 on a 41-yard field goal by Matt Stover.
The first lapse in the second half by the Ravens' defense cost it. After failing to get a first down on seven consecutive drives, St. Louis quarterback Marc Bulger hit Dane Looker for a 24-yard pass, setting up a 49-yard field goal by Wilkins that pushed the Rams back ahead 24-22 to start the fourth quarter.
Besides that, the Ravens' defense was stout, holding the Rams to seven first downs and an average of 2.4 yards per play.
"We played a good game defensively, but that is not our goal," defensive end Tony Weaver said. "Our goal is to win and we couldn't do that tonight."
The Ravens paved the way for the Rams to pull away in the end, turning the ball over on three of their four fourth-quarter possessions.
While the offense gave the ball away repeatedly, the defense remained stingy. The Rams' six scoring drives were for 36, 1, 32, 8, 4 and 26 yards.
"Our defense gave them nothing. Nothing," Billick said. "And that's encouraging."
The Ravens faced their largest first-quarter deficit of the season, spotting the Rams a 14-0 lead as a result of a drop and a hop.
After two big runs by Lewis put them deep in Rams territory, Boller's third-down pass sailed through the hands of receiver Travis Taylor and to St. Louis cornerback Jerametrius Butler. That set up the Rams' first touchdown.
Less than two minutes later, a punt by the Ravens' Dave Zastudil hit the Rams' 40-yard line and bounced 15 yards backward on the artificial surface, where St. Louis' Looker picked it up and ran it to the Ravens' 1.
On the next play, Faulk scored his second touchdown to stake the Rams to a 14-0 advantage just 5:32 into the game.
The Ravens closed within 14-12, only to see the momentum slip away.
Lewis tried to pick up Rams safety Adam Archuleta on a blitz up the middle and inadvertently bumped into Boller, who was attempting to rush a throw. The ball slipped out of Boller's hands and Archuleta grabbed it off one bounce, racing 45 yards for the touchdown.
Boller's ninth fumble of the season expanded St. Louis' advantage to 21-12.
"I think that play completely demoralized them," Rams coach Mike Martz said.
The Ravens' offense simply was their defense's worst enemy last night.
"We're really going to have to get focused this week and for the rest of the season," said Ravens tight end Todd Heap, who had six catches for 49 yards. "We can't play like that anymore."