Kellen Clemens is still getting to know his teammates. The stand-in quarterback did just about as well as could be expected running the NFL's worst offense.

Making his first start in two years, Clemens was 25 of 36 for 229 yards and a late touchdown pass to Danario Alexander in the St. Louis Rams' 20-13 loss to the Cincinnati Bengals on Sunday. Clemens had only seven practices before stepping in for Sam Bradford and A.J. Feeley, both out with injuries.

Bradford did not practice all week and missed his fourth start with a high left ankle sprain and Feeley was out for the second straight week with a fractured thumb. Enter Clemens, who was signed last week.

Clemens began a postgame news conference by jokingly introducing himself: "I'm Kellen. Nice to meet you." Then he accepted responsibility.

"When you don't score as many points as the other team, then that falls on the quarterback," Clemens said. "Explosive plays would have been nice."

The Rams were 2 for 13 on third down, but coach Steve Spagnuolo had only positives for Clemens.

"He goes in there, manages the huddle, he's making suggestions, he's running the two-minute offense," Spagnuolo said. "Extremely proud of Kellen."

Rookie A.J. Green had six catches and topped 1,000 yards for the season, helping the Bengals (8-6) keep pace in the AFC playoff race.

Brandon Tate's 56-yard punt return set up Bernard Scott's go-ahead touchdown run late in the third quarter and Cedric Benson added a short scoring run in the fourth for the Bengals, who won for only the second time in six games.

Cincinnati entered a game behind the New York Jets, who were playing at Philadelphia, for the final AFC wild-card berth.

Green caught a 55-yarder to set up a field goal for the game's first score. He has 1,006 yards receiving, leaving him 3 shy of Cris Collinsworth's franchise rookie record in 1981.

St. Louis has lost five in a row, and Spagnuolo is 10-36 winding down his third season.

"I know the goals and objectives we set for this year are no longer attainable, other than celebrate an NFL win in the locker room," Spagnuolo said. "The mindset will be in some ways to continue to build and do the right things to build. We owe that to the organization, I owe that to the organization, I owe it to the players."

The Rams totaled 6 yards on third down, and didn't convert until late in the fourth quarter. Plus, they were whistled for 109 yards on 10 penalties, including a handful of critical calls in the second half.

About a dozen former teammates from the Rams' 2000 Super Bowl championship team attended a halftime ceremony in which Hall of Famer Marshall Faulk was added to the ring of fame in the Edward Jones Dome. Several others, including Kurt Warner, Dick Vermeil and Isaac Bruce, weighed in with video tributes.

"To every coach, trainer and equipment manager, and everybody who had a hand in any small detail in my life to make this experience what it is, I want to thank you," Faulk said. "I will cherish this and cherish all the moments and people I've worked with with the Rams."

The Rams wore throwback uniforms honoring that era, hoping to recapture the form from their best game of the year, an out-of-nowhere upset of the Saints in Week 7 for their first victory. Though technically a sellout, attendance of 56,431 was about 9,000 shy of capacity and the stadium looked to be little more than half-full.

Cincinnati won despite an off-game from rookie Andy Dalton, who was 15 for 26 for 179 yards with an interception and no touchdowns to end a pair of lengthy streaks. He had gone 107 passes before Josh Gordy's interception in the third quarter, and had thrown at least one TD pass in 10 consecutive games.

Tate's punt return, plus a personal foul on James Butler for pushing him while out of bounds, put the Bengals at the 12 and set up Scott's 1-yard run for a 13-6 lead in the final minute of the third quarter. Two unnecessary roughness calls on linebacker Chris Chamberlain put the Bengals on the doorstep for Benson's 4-yard scoring run with 9:14 to go.

Green had four catches for 94 yards in the first half before leaving with a right shoulder injury after getting tripped by Gordy on a pass interference call in the second quarter. Green had been questionable to return, but was on the field to start the second half.

The teams were a combined 0 for 10 on third down in the first half, with the Rams failing six times, and each totaled just 132 yards.

Green got behind two safeties on what might have been busted coverage on a 55-yard reception to the 2 to set up a field goal for the game's first score, not long after a roughing the passer call on Eugene Sims kept a drive alive.

Josh Brown missed a 45-yard attempt, but connected from 26 and 43 yards late in the first half to give the Rams a 6-3 lead.