After spotting the Vikings a 10-0 lead, the Rams scored the game's next 15 points to take a five-point lead to the break.
The Rams cut into the Minnesota lead again early in the second quarter as Greg Zuerlein took advantage of a strong wind to boot a 61-yard field goal to make it 10-9 with 10:55 to play before halftime.
The kick, the seventh-longest in NFL history, was a career-best for Zuerlein. His previous long-range kick, a 60-yarder, came at home against Seattle in 2012, Zuerlein's rookie season.
Later in the half, after a drive 12-play, 57-yard drive featuring a steady diet of Todd Gurley and Tavon Austin reached the Minnsota 17, Zuerlein kicked a 35-yarder that put the Rams up 12-10 with 3:23 left in the first half.