St. Louis ? In their season finale, the St. Louis Rams looked more like defending NFC champions than the underacheivers who finished two games below .500.

Dre’ Bly returned a fumble 20 yards for a touchdown and the Rams scored 28 fourth-quarter points to go out as winners, beating the playoff-bound San Francisco 49ers 31-20 Monday night.

“I wish we’d have played a little better in the first half,” coach Mike Martz said. “But what the heck.”

Bly stripped Garrison Hearst after a screen pass for the first scoring return all season by the Rams (7-9).

“It ended the season in a perfect way,” Bly said. “It’s a tremendous way to finish and it’s a great feeling.”

The NFC West champion 49ers (10-6) played a game of keep-away in the first half, taking a 17-0 lead as they tuned up for next week’s wild-card playoff game against the New York Giants.

“We had 33 yards at halftime,” Martz said. “I was getting ready to check the paper to look for a job.”

Then the Rams rallied against a 49ers defense largely populated by second-teamers.

“As a coach you want to keep playing, put the pedal to the metal so to speak,” coach Steve Mariucci said. “Then there is the side of you, in the back of your mind, that says, ‘Get these guys fresh and healthy and not produce any more injuries for the next game.”‘

Jamie Martin, who didn’t start because of a bruised left knee that kept him out of three practices last week, hit Brandon Manumaleuna for a 6-yard touchdown pass and Isaac Bruce for a 26-yarder that cut the Rams’ gap to three points with 7:09 to go.

On the first play after the ensuing kickoff, Bly put them over the top.

Hearst’s fumble with 2:51 to go, forced by Leonard Little and recovered by Dexter McCleon at the St. Louis 49, finished off the 49ers. Martin, who was 22-for-35 for 245 yards and a career-best three touchdowns, tacked on a 32-yard scoring pass to Ernie Conwell with 1:53 remaining to complete the comeback.

Jeff Garcia opened the game by directing the NFL’s longest-lasting drive of the year as the 49ers chewed up 12:07 on a 20-play, 81-yard march capped by Jeff Chandler’s 19-yard field goal.