The Stormers had to withstand a ferocious comeback by the Cheetahs before clinching a 16-14 win in a Super Rugby hemisphere championship match at Newlands on Saturday.
It was the ninth win in 10 matches for the Stormers, but the Cape side once again failed to secure an attacking bonus point.
Despite having five Springboks in their backline, the only Stormers try in the South African derby came from a forward rush and they seldom mounted any significant attacks.
Stormers have scored only 17 tries in 10 matches and centre and captain Jean de Villiers admitted: "It wasn't our best performance.
"If we want to play like this I can't see us going further in this competition. We need to go back to the drawing board and play better next week and in the two weeks after that, otherwise we are in trouble."
Despite having won one more match than Northern Bulls, Stormers trail their South African conference rivals by a point because the Pretoria side have collected six bonus points.
Stormers led 16-0 at half-time through a try by lock Eben Etzebeth and three penalty goals and a conversion by fly-half Peter Grant.
Lock Andries Bekker came close to scoring at the start of the second half but was tackled into touch and the Stormers squandered an attacking opportunity soon after when they were awarded a five-metre scrum but then conceded a penalty.
Fortunes changed dramatically as the Cheetahs dominated possession for the rest of the match and scored tries through full-back Hennie Daniller and left wing Willie le Roux, both converted by replacement fly-half Riaan Smit.
Whereas in the first half the Cheetahs had difficulty keeping on the right side of referee Steve Walsh in the scrums and mauls, it was the Stormers who conceded a string of penalties, especially in the scrums, in the second half.
Stormers flank Rynhardt Elstadt was given a yellow card for kneeing an opponent midway through the second half and there was a mass brawl soon after which resulted in Walsh issuing a white card, meaning the incident will be reviewed by the match commissioner.
Cheetahs captain Adriaan Strauss said: "We had a shocking first half but I am proud of our second-half performance."
STORMERS 16 (Eben Etzebeth try Peter Grant con 3 pens) bt CHEETAHS 14 (Hennie Daniller, Willie Le Roux tries Riaan Smit 2 cons) at Newlands Rugby Stadium. Referee: Steve R. Walsh.