Joe Pietersen scored 13 points to help the Stormers maintain their excellent start to the Super 14 campaign with a hard-fought victory over the Cheetahs in Cape Town.
Jaque Fourie was also among the points as the Newlands outfit outscored the visitors by two tries to one, the solitary effort from the Free Staters coming from Meyer Bosman.
But it proved only a consolation with the hosts holding out to stay in second place.
They were ahead after just three minutes when Hennie Daniller was penalised for being in front of the kick, allowing Pietersen to send over the three points from close to the halfway line.
The lead was doubled shortly after, this time the penalty coming after the visitors collapsed the maul, before the opening try in the 24th minute.
It came after more dominant play by the home forwards, who worked the ball through the phases on to Anton van Zyl, Fourie and then Pietersen to run in on the left.
The extras were added as well, but Bosman's clever kick ahead bounced kindly for Robert Ebersohn to draw two defenders and pass back to his midfield partner at the same time as the visitors hit straight back.
Naas Olivier missed the easy conversion, but then joined his team-mates in defence to help frustrate the hosts, who enjoyed plenty of possession before half-time, by keeping the scoreline the same at the break.
Both sides had chances to score after the restart, but were let down by errors just short of the line.
It took a stunning 40-metre drop goal by Olivier from the left to break the deadlock, but another piece of brilliance by Schalk Burger led to a second try for the home side.
The South Africa flanker looked to have been pushed too wide by the visiting defence, but as he headed for touch, he managed to squeeze a pass to Fourie to score.
Willem de Waal, who took over the kicking duties after Pietersen was injured and replaced at the break, missed the conversion, before Olivier exchanged the favour by wasting a penalty for his side.
But De Waal made no mistake with his next kick - awarded after the Cheetahs lost the bind at the scrum - giving the Stormers a 21-8 lead with 19 minutes to play.
And the score-line remained that way until the end as Allister Coetzee's team maintained their flying start to the season.