INDIANAPOLIS -- There was no chance of a stunning comeback for Andrew Luck this time.
The Colts quarterback has become known for his late-game magic, but he made too many mistakes to add to his reputation and got little support in St. Louis' 38-8 win on Sunday.
Luck helped the Colts rally from an 18-point deficit the previous week to beat the Houston Texans. By the start of the fourth quarter against the Rams, Indy trailed by 30 points. Rams cornerback Trumaine Johnson, who intercepted one of Luck's passes, said the Rams talked about Luck's history during the game.
"They call him 'The Comeback Kid,'" he said. "You can never give up with him."
The Rams' defensive line bothered Luck all day. He passed for 353 yards, but threw three interceptions and was sacked three times.
"We knew our D-line was going to get there, so we're just back there watching," Johnson said. "Watching Andrew Luck, watching his eyes."
Colts coach Chuck Pagano hinted that maybe his team has gotten too comfortable with Luck's bailouts. Luck has led 10 game-winning rallies in the fourth quarter or overtime in his two-year career.
"Not enough rabbit's feet in the pocket," Pagano said. "And again, we're playing a good football team that came ready to play."
While the Rams' defense was controlling what had been one of the league's best offenses, Tavon Austin, a rookie receiver from West Virginia, was having a breakout game on offense. He caught two passes for 138 yards and two touchdowns and returned a punt 98 yards for another score for St. Louis.
"It's definitely boosts your confidence that you can play in this league," Austin said. "You're going to go from here and keep going hard, keep the same passion now. Celebrate on the plane going back, and tomorrow's a new day."
Rams quarterback Kellen Clemens completed 9 of 16 passes for 247 yards and two touchdowns for the Rams (4-6), who snapped a three-game losing streak.
Wide receiver T.Y. Hilton caught seven passes for 130 yards and running back Donald Brown caught five passes for 64 yards and a touchdown for the Colts (6-3).
The loss was unexpected for Indianapolis, which has wins over top teams San Francisco, Seattle and Denver. It was the worst home defeat for Indianapolis since a 31-0 loss to San Diego on Nov. 29, 1993.
"They beat us fair and square, in every which way they possibly could," Luck said.
Rams defensive end Robert Quinn sacked Luck and forced him to fumble, and defensive end Chris Long scooped the ball up and ran 45 yards for a touchdown just under three minutes into the game.
"That stunk," Luck said. "Terrible way to start."
A 35-yard pass from Clemens to receiver Chris Givens set up running back Zac Stacy's 1-yard touchdown run to push St. Louis' lead to 14-0.
Austin's long punt return gave the Rams a 21-0 edge with 10:28 left in the second quarter. He caught the ball on a bounce before taking off.
"It was a 'Peter' call," he said. "I waved them off. I should have caught the ball. I had to make a decision, so I had to stop there, and I just pretty much returned it, and my blockers were available and I made a great play."
Austin struck again with a 57-yard touchdown reception to increase the Rams' advantage to 28-0 with 6:58 left in the second quarter, a margin they carried into halftime. The Rams outgained the Colts 170 yards to 74 in the first half.
Austin struck again 65 seconds into the second half with an 81-yard touchdown catch and run.
The Colts finally scored when Luck found Brown for a 13-yard touchdown pass. Luck connected with tight end Coby Fleener for the 2-point conversion, but the Rams still led 38-8 late in the third quarter.
The Colts play at Tennessee on Thursday, and Luck can't get back on the field soon enough.
"You want to get back out there and get that taste out of your mouth," he said.
The Rams had lost their previous two games by a combined 12 points, but now, St. Louis now has something positive to build on heading into its bye week.
"We're 4-6, and it's a win," Johnson said. "The last few weeks, we've been coming close. I'm just glad we got this one."
NOTES: Cassius Vaughn started at left cornerback in place of Greg Toler for the Colts. Toler has a groin injury. ... It was the Rams' first trip to Lucas Oil Stadium. St. Louis' previous trip to the city was in 2005. ... Colts WR T.Y. Hilton entered the game with five touchdowns of 50 yards or more since the start of the 2012 season, second in the NFL to Minnesota Vikings RB Adrian Peterson. ... Rams RB Isaiah Pead was penalized for unsportsmanlike conduct on the opening kickoff.