The game begins at 4:05pm eastern time and will be shown by FOX, or watch a live stream online by purchasing NFL Sunday Ticket Max.
Griffin, who was named the NFC's Offensive Player of the Week, led the Redskins with a dominating display in their 40-32 win against the New Orleans Saints and Drew Brees.
The Heisman-winning Baylor alum went 19-for-26 for 320 yards, including an 88-yard touchdown strike while falling to the ground to wide out Pierre Garcon.
Garcon was Griffin's top target against the Saints, but is questionable Sunday with a foot injury. He did practice Friday and is expected to play.
Running back Alfred Morris also displayed why he is head coach Mike Shanahan's top rusher, gaining 96 yards on 28 rushes and scoring two touchdowns.
Similar to the Redskins, the Rams caught the Detroit Lions off-guard but didn't achieve the same result.
St. Louis scored 13 points off of Detroit quarterback Matthew Stafford's three interceptions, but collapsed in the fourth quarter and gave up a 5-yard touchdown pass from Stafford to running back Kevin Smith with 10 seconds left for a 27-23 letdown.
Rams quarterback Sam Bradford cut down on the turnovers that plagued him last season and went 17-for-25 for 198 yards and one touchdown. Bradford put together two drives that led to scores, including one that set up a 46-yard field goal by kicker Greg Zuerlen with 1:55 left for a 23-20 lead, but the Lions pulled out the late victory.
Signed during the offseason, cornerback Cortland Finnegan ran back an interception 31 yards for a touchdown and a 13-7 St. Louis lead.
Running back Stephen Jacksons only managed 53 yards on his 21 carries, and wide receiver Danny Amendola grabbed five receptions for 70 yards.
Betting Odds: Washington Redskins is favored by 3 points.
Prediction: St. Louis will field a far tougher secondary than Griffin faced against the Saints, but Washington was most effective their quick, short passes that led to big gains. While he did run for 42 yards on nine carries, Griffin could break away for more yardage if the Rams secondary blankets his receivers.
Predicted Score: Washington 20, St. Louis 13