Not only did the Bills lose Sunday, star RB Fred Jackson suffered a leg injury. (US Presswire)

For the second time this season, the Bills passed up an opportunity for three points in a close, low-scoring game.

And for the second time this season, it cost them in the end.

The Bills (5-8) fell to the St. Louis Rams (6-6-1) at Ralph Wilson Stadium Sunday, 15-12, largely due to a questionable -- and conservative -- decision from coach Chan Gailey.

Following a botched punt by the Rams, the Bills began the fourth quarter with the ball at midfield and a five-point lead. The drive stalled at the St. Louis 34, and the Bills originally were going to attempt a 52-yard field goal from K Rian Lindell (who has missed only one kick this season). Lindell said after the game that he was connecting from 55 yards out during pre-game warmups. Gailey changed his mind -- burning a timeout in the process -- and the Bills punted instead. A field goal then would have later forced overtime. The Bills could have also gone for it on 4th-and-7, given their placement on the field.

“We weren’t going to go for it there,” Gailey said. “The defense was playing good, we were going to try and pin him back. And when they first told me they said it was a 50-yard field goal instead of a 52, 53-yard field goal and we had just dropped a snap on the extra point so that’s why I pulled them back out of there and say, 'Hey, let’s let the defense try to pin them back.'"

It’s the second time this season such a decision has come back to haunt the Bills. In a 20-13 loss to the Indianapolis Colts in Week 12, Gailey had the Bills punt from the Colts 34 despite Lindell’s success and an indoor environment.

That wasn’t the only debatable call Gailey made against the Rams. Before the end of the first half, the Bills badly mismanaged the clock and ended up with a 40-yard field goal instead of possibly more.

The loss overshadows another strong performance from Buffalo’s resurgent defense -- the fourth impressive game in as many weeks. The Bills held the Rams to 78 yards on the ground and got after QB Sam Bradford (one sack, four QB hits) in the passing game.

The Rams, meanwhile, continue to surge under new coach Jeff Fisher. They showed tremendous resiliency on their game-winning drive, moving 84 yards down the field and converted three third-down attempts. Bradford ended the drive with a pretty 13-yard pass over the middle to WR Brandon Gibson.

When the game turned: The momentum shifted after Gailey’s fourth-quarter decision. But the Bills had two more chances after that -- and it was St. Louis’ game-winning drive that finally turned the game for good.

Highlight moments: Bradford’s touchdown throw to Gibson has to top the list. It capped a gutsy drive from the young QB. Bills CB Stephon Gilmore had one of the only highlights of the first half, picking off a Bradford pass. The pass was initially tipped by Bills LB Bryan Scott and fell into Gilmore’s arms. The rookie ran it back for a touchdown, but the score was negated due to a block in the back penalty on DE Kyle Moore.

Top-shelf performances:

  • Rams QB Sam Bradford -- 19 of 39, 209 yards, 1 TD, 1 INT

     
  • Rams WR Brandon Gibson -- 6 receptions for 100 yards and the game-winning TD

     
  • Bills TE Scott Chandler -- 5 receptions for 71 yards
     

What they said about Buffalo’s inability to finish:

  • Bills QB Ryan Fitzpatrick: “We have to develop a killer instinct. We have to win those games if we want to be one of the teams that is sitting there at the end of the year getting ready for the playoffs.”
     
  • Bills coach Chan Gailey: “We are not making the plays to win ball games. That’s what winning teams do. ... We have to do that or we will not get over the hump.”

Numbers you should know: The Rams took advantage of Buffalo’s banged up offensive line, picking up five sacks and 11 QB hits.

Injury update: Bills -- RB Fred Jackson was carted off the field late with what appeared to be a right leg injury. Gailey didn’t have an update on Jackson after the game. FS Jairus Byrd (leg contusion) and DT Marcell Dareus (undisclosed) briefly left the game but both returned: Rams -- OT Roger Saffold tried to battle through a back injury but had to leave the game on two separate occasions. S Craig Dahl left the game and was evaluated for concussion-like symptoms.

Going forward: Bills -- The Bills are now all but mathematically eliminated from the playoffs (Buffalo is two games behind Cincinnati and Pittsburgh with three games to play). Remarkably enough, both Pittsburgh and Cincinnati lost on Sunday, which means the Bills would have been only one game out of a playoff spot had they won. Buffalo has a “home” game in Toronto next week against Seattle. Rams -- St. Louis has a home game against Minnesota next week before ending the year on the road against Tampa Bay and Seattle.

For more updates on the Bills, follow correspondent Mark Ludwiczak on Twitter @CBSBills and @MarkLud12.

Get more Rams updates and analysis from Larry Hartstein on Twitter @CBSRams.