The Bloemfontein-based Cheetahs remain sixth in the competition standings, the final playoff position, but now face a nervous final two weeks of the regular season with a number of sides closing in behind them.
One of those is the Stormers, whose own playoff hopes had looked grim just a few weeks ago. They have now moved to within four points of the Cheetahs and were delighted with the way they neutralised their opponents' exciting running backs and disrupted their set-piece ball.
"The plan was just to stick to the game we wanted to play and our individual errors were much less than previously," Stormers stand-in skipper Deon Fourie said.
"The Cheetahs rely a lot on their set-pieces and I think we did well there."
Fourie was one of three try-scorers for the home side with Siya Kolisi and Springbok winger Bryan Habana the others.
The Stormers' driving maul has been a feature of their play all season and they used it to good effect to get the only five-pointer of the first half.
A relieved Fourie barging over after he opted not to go for goal having being awarded a penalty following 17 phases camped on the Cheetahs line.
Flyhalf Riaan Smit had given the visitors the early lead with a penalty but they would prove to be the Cheetahs only points of the match as the Stormers held a 10-3 lead at halftime.
Joe Pieterson added two more penalties after the break to boost the hosts' advantage as they put the squeeze on the Cheetahs attacking play and controlled territory.
That dominance began to translate on to the scoreboard when Kolisi scored the Stormers' second try. His angled run bamboozled the Cheetahs defence after being fed by scrumhalf Louis Schrueder from close range.
The game was then made safe for the Stormers just a few minutes later when a breakaway created a four-on-two attacking situation. Flanker Nizaam Carr looked to have butchered the try when he failed to spread the ball wide, but quick recycling resulted in Habana crossing in the corner.
"It's a very disappointing result, definitely the shocker of the year for us," Cheetahs captain Adrian Strauss said.
"We need to have a hard look at ourselves and then write this one off. The lineouts were good, but scrum time we gave away a lot of penalties.
"We are still in the running and we will bounce back. I have full confidence in the guys."
The Cheetahs will be guaranteed four points from a bye in the final week of matches, but will likely need a victory over the Blues next Saturday to secure a playoff spot.