ST. LOUIS — About the only thing missing from Peyton Manning's day was a sixth straight 300-yard passing game.

It wouldn't have been appropriate for the Indianapolis Colts quarterback to try to tie the NFL record the way his unbeaten team was beating up on the woeful St. Louis Rams.

Manning was 23 for 34 for 235 yards and three touchdown passes and the defense got its first score of the year on rookie Jacob Lacey's 35-yard interception return in a 42-6 rout Sunday. Looking fresh coming off their bye, the Colts won their 15th straight regular-season game and set a franchise record with their eighth straight road victory.

There were plenty of cheers from a sellout crowd that included a healthy contingent of Indianapolis fans, many who lingered to salute players after the game.

The Colts are 6-0 for the fourth time in five seasons.

The Rams (0-7) lost their 17th straight regular-season game, wasting a season-best 134 yards on 23 carries by Steven Jackson. St. Louis' highlight came on its opening drive, a 50-yard flea-flicker from Marc Bulger to Donnie Avery to the Colts 14, but the drive fizzled and the Colts forced a short field goal.

The Colts intercepted Bulger twice and Dwight Freeney ran his sack streak to seven straight games — three off the NFL record — by beating rookie Jason Smith. Safety Bob Sanders got out of his season debut unscathed.

Indianapolis' offense had plenty despite losing Reggie Wayne (groin) for a quarter and Donald Brown (shoulder) for most of the last three quarters. And without big numbers from Manning, who missed a chance to tie Steve Young, Kurt Warner and Rich Gannon for the longest string of 300-yard games in NFL history.

Manning wasn't sacked and rarely touched. He did hit one milestone, passing Warren Moon for fourth on the career completion list.

Wayne had seven catches for 83 yards with a 6-yard scoring reception on the opening drive, but seemed to lack burst after returning and had one catch for 7 yards the rest of the way.

There's been no suspense to the Colts' last four games, won by a total of 138-42. That no doubt hurt Manning, who had 24 yards passing in the fourth quarter, although that total included an 8-yard scoring pass to Austin Collie.

NOTES: Rams long snapper Chris Massey (left knee) was carted off in the second quarter. ... Rams OG Richie Incognito (left foot) limped off in the fourth quarter. ... The Colts' Kelvin Hayden, who intercepted Bulger in the fourth quarter, missed the previous three games with a hamstring injury. ... The Colts are 5-0 coming off the bye week since 2005.