“I want to be great and I have confidence in myself that I can be great,” he said.
The Vikings signed him to be a backup and he has made the most of his opportunities with Sam Bradford injured and Teddy Bridgewater recovering from a knee injury.
Keenum was 21 of 30 for 282 yards with both touchdown passes going to Kyle Rudolph, giving the Vikings a 20-3 lead late in the second quarter.
“Case is amazing because he does so many small things to pick up first downs and keep drives alive,” Rudolph said.
“Every time he finds a way to convert another third down, it means we've got three more plays to attack the defense. With the number of big-play guys we've got now, we can do a lot of damage with those three plays.”
Detroit (6-5) made mistakes in every phase of the game and Minnesota took advantage. Keenum's 1-yard pass to Rudolph was made a little easier because the Lions had just 10 defenders on the field.
And, Keenum's 9-yard run came after Matthew Stafford was charged with a fumble while trying to hand off to Ameer Abdullah.
Instead of winning to pull within a game of Minnesota and having a potential tiebreaker, the Lions' loss hurts their chances of making a second straight postseason appearance.
“Don't count us out just yet,” Detroit coach Jim Caldwell said. “We've got a lot of football yet to play.”
Minnesota's Adam Thielen had eight receptions for 89 yards and deflected credit to his quarterback.
“Case Keenum is one tough human being,” he said. “When he's hanging in there — giving you time to get open — you feel like you're letting him down if you can't do it. He's willing to get crushed to make a play, and that makes us want to come though on our end.”
Everson Griffen had two sacks, tying his career high with 12 on the season, for the Vikings.