Bradford, the No. 1 overall pick, had the best game of his young career. He completed 22 of 37 passes for 308 yards and three touchdowns and a quarterback rating of 113.3, all career highs.
Bradford distributed passes to nine different receivers, including rookie Danario Alexander. The University of Missouri product returned after missing the last four games because of a knee injury to catch four passes for a career-high 95 yards.
The rookie quarterback threw two touchdown passes to Billy Bajema, the first scores of the tight end's six-year career. He also connected with rookie tight end Michael Hoomanawanui for a 36-yard touchdown pass.
Running back Steven Jackson rushed for 72 yards on 29 carries.
The Broncos (3-8), who got 347 passing yards and three touchdowns from quarterback Kyle Orton, led 10-0 early in the first quarter.
But the Rams responded with a 33-3 run — including two field goals from Josh Brown and a 1-yard touchdown run by backup running back Kenneth Darby — to take control of the game going into the fourth quarter.
The Broncos scored 20 points in the final quarter, including two touchdown receptions from Brandon Lloyd, but Brown's third field goal of the game turned out to be the difference.