Robert Griffin III, the Redskins' sensational rookie quarterback, sprained his right knee in the fourth quarter Sunday.
[Updated, 4:50 p.m.: Griffin's availability for next week has yet to be determined, but an X-ray and an MRI exam revealed no major damage to his knee, including the major ligaments. A team spokesman said "everything was clear" regarding any significant damage.]
"I still felt like I could go out and help the team win," Griffin said after the game. "I feel pretty good. I'll fight."
The dual-threat Griffin, who has already broken the single-season rookie quarterback rushing record set by Carolina's Cam Newton last season, was crushed by Ravens defensive tackle Haloti Ngata after picking up 13 yards on a scramble.
Griffin left the field for one play and tried to return but he lasted only four more plays before dropping to the ground in pain.
"I wanted them to know I wanted to go back in and I did," Griffin said. "I knew when enough was enough.
“I knew I needed to get out at that point. I couldn't move. At some point, you have to do what's right for the team. And if I'm playing the rest of that game, I probably would have hurt myself even more.”
Backup quarterback Kirk Cousins connected with Pierre Garcon for an 11-yard touchdown pass with 29 seconds left bring the Redskins to within two points of Baltimore. Cousins then ran in the two-point conversion to tie the score 28-28, and force overtime.
Kai Forbath hit a 34-yard field goal in extra time to give the Redskins their fourth straight victory and a winning record at 7-6.
Griffin completed 15 of 26 passes for 246 yards and a touchdown pass while he gained 34 yards in seven rushes.