BALTIMORE -- Any excitement over the Baltimore Ravens' thrilling come-from-behind victory over the St. Louis Rams on Sunday was tempered by season-ending injuries to both quarterback Joe Flacco and running back Justin Forsett.

A sack and forced fumble by Baltimore linebacker Courtney Upshaw set up a 47-yard, game-winning field goal by Justin Tucker as time expired to give the Ravens a 16-13 victory over the Rams on Sunday.

The win, however, came at a huge cost.

Flacco could have torn both his ACL and MCL in his knee, which might jeopardize the start of next season. Forsett has a broken arm and his long-term prognosis is uncertain.

In a season where little has gone their way, this is perhaps the biggest blow Baltimore (3-7) could have suffered.

"It's tough," Flacco said. "I don't think it's totally set in yet, but it's the nature of the game, man. Stuff like this happens. You just have to stand tall and get through it."

Upshaw hit Rams quarterback Case Keenum from the blind side, and the ball was recovered by defensive end Lawrence Guy at the Saint Louis 41. Baltimore kept the ball on the ground until the attempt by Tucker, who had just missed a 51-yard attempt on the previous drive.

"No one even batted an eye when I missed," Tucker said. "I came to the sidelines and everybody was the same positive Ravens that I know."

Flacco overcame a pair of costly interceptions, orchestrating three fourth-quarter scoring drives. He was 27 of 44 for 299 yards and a touchdown. Backup Matt Schaub will start Monday night against the Cleveland Browns.

Forsett suffered a broken right arm when he got slammed to the turf by Rams defensive tackle Aaron Donald late in the first quarter.

"Obviously, it's tremendously disappointing for those guys," Ravens coach John Harbaugh said. "We'll be fine as a football team. We'll bounce back. That's what you do."

A fumble by Rams running back Todd Gurley was recovered by Ravens linebacker Albert McClellan on Rams 42. On the ensuing drive, however, Flacco threw an interception to St. Louis cornerback Trumaine Johnson.

Two plays later, Keenum lobbed a 30-yard touchdown pass to tight end Lance Kendricks to extend the Rams' lead to 13-3 with 6:14 left in the third quarter.

Another fumble by Gurley early in the fourth quarter led to a 3-yard touchdown pass from Flacco to wide receiver Kamar Aiken that that cut St. Louis' led to 13-10 with 11:11 left in the game. A 20-yard field goal by Ravens kicker Justin Tucker tied the game at 13 almost six minutes later.

St. Louis kicker Greg Zuerlein missed a 52-yard field goal attempt with 1:41 left in the game that would have provided the lead. Tucker eventually made them pay as he hit the game-winning kick as time expired.

"Probably one of the hardest (losses) that I've been around since I have been here," said Rams coach Jeff Fisher, whose team fell to 4-6. "It's difficult when you lose that way in a game that you somewhat controlled or dictated and gave up a big lead.

Keenum, who got his first start after Nick Foles was benched last week, was 12 of 26 for 136 yards with a touchdown. Keenum was evaluated for concussion after game, which could jeopardize his start next week at Cincinnati.

The Ravens managed the victory despite committing 10 penalties for 137 yards. Ravens tight end Crockett Gillmore had five catches for a career-high 101 yards.

A 49-yard pass interference penalty by Baltimore cornerback Jimmy Smith gave the Rams the ball on the 10-yard line. Gurley made the Ravens pay as he carried the ball three straight times and got in the end zone from the 1 to provide a 7-0 lead with 2:05 left in the first quarter.

The Ravens finally got a break when Tavon Austin fumbled a punt that was recovered by C.J. Mosley at the Rams' 31. However, Baltimore could only manage a 25-yard field goal by Tucker and trailed 7-3 at the break.

St. Louis had 74 yards of total offense in the opening half.

"It's all about execution," Rams tight end Jared Cook said. "We just kept shooting ourselves in the foot today. We didn't finish drives and we had too many turnovers."

NOTES: Former Ravens S Ed Reed was inducted into the team's "Ring of Honor" at halftime. Reed is the franchise's all-time leader with 61 interceptions. ... Rams WR/PR Tavon Austin played football for nearby Dunbar High School. He won three consecutive state championships at M&T Bank Stadium. ... The Rams last victory in Baltimore came in 1969 when they beat the old Colts at Memorial Stadium.