ORCHARD PARK, N.Y. - Bills cornerback Terrence McGee had trouble figuring out who Willie Parker was even after the game ended.

"I still don't know who that is," McGee said. "Who is this Willie Parker?"

You know, Willie Parker, the fourth-string running back who had 102 yards rushing and helped a collection of Steelers backups knock Buffalo out of the playoffs.

Resting most of their starters, including Ben Roethlisberger and Jerome Bettis, the playoff-bound Steelers showed they can win with backups, beating the Bills 29-24 on Sunday.

The Steelers won their 14th straight to match a single-season record set by Miami in 1972, and became just the fourth team in NFL history - and first in the AFC - to finish 15-1.

They won with Parker, an undrafted free agent, who became only the third player to have 100 yards rushing against what had been a stingy Buffalo defense this season.

They won with third-string quarterback Brian St. Pierre running the offense with the game on the line.

And they won with backup linebacker James Harrison, another undrafted free agent, returning a fumble 18 yards for what proved to be the decisive score.

"If there was a team that you could put up as a poster boy for a 53-man roster, it's us," St. Pierre said.

"It was a whale of a game," coach Bill Cowher said. "We were playing to win this football game. ... These are the same guys we may need in the playoffs."

The Steelers had already clinched home-field advantage before the game. They now have a two-week wait to determine who they'll play.

The Bills have a long offseason to ponder what went wrong.

So much for the resilience Buffalo (9-7) showed in winning six straight and nine of 11 to overcome an 0-4 start. So much for making the playoffs for the first time since 1999.

The Bills' loss clinched a berth for the New York Jets despite their overtime loss to St. Louis.

"Pretty angry. ... I'm a little bit in shock," said a red-eyed Drew Bledsoe. "The bottom line is if we can't beat them with their backups on the field, then we probably don't deserve to be in."

"It's frustrating because I want more for this organization, especially the fans," receiver Eric Moulds said. "I feel like they deserve more than what we showed today."

The Bills looked nothing like a team that outscored its opponents 228-89 in its previous six games.

Buffalo managed just 267 yards, with seven three-and-outs. And the defense couldn't get the Steelers off the field, losing the time-of-possession battle by more than 11 minutes.

The game turned late in the third quarter after Rian Lindell missed wide right on a 28-yard field goal that left the Bills clinging to a 17-16 lead.

The Steelers responded with 10 points in an 85-second span at the start of the fourth quarter.

The decisive play came when Bledsoe was blind-sided by rookie cornerback Ricardo Colclough, who forced a fumble that fell directly into Harrison's hands.

The Bills went three-and-out on their next possession, and the Steelers then ate up nearly nine minutes with a 14-play, 46-yard drive, capped by Jeff Reed's 33-yard field goal.

"It says a lot about the backups and the character of this team," Harrison said. "It's a sense of pride. You don't want to lose to anybody."

Notes:

Steelers WR Antwaan Randle El scored on a 16-yard touchdown reception, and Reed hit five field goals, the longest from 37 yards. ... Bills RB Willis McGahee had 79 yards rushing and two touchdowns. Cornerback Nate Clements also returned a Tommy Maddox interception 30 yards for a touchdown. Lindell hit a 37-yarder. ... Bledsoe finished 16-of-30 for 189 yards. The former Patriots star has 10,151 yards passing in three seasons with Buffalo, becoming only the seventh NFL player to surpass 10,000 yards with two teams. ...