Stormers (15) 28
Jaguares (6)   20
A massive scrum by a depleted Stormers pack won the home team a game that should never have been that close to start their Super Rugby campaign on a positive note.
Stormers hooker Ramone Samuels was sin-binned for killing the ball in the 65th minute.
The Jaguares earned a penalty try from a scrum close to the Stormers line immediately afterwards as they tried to match the visitors with seven men.
With seven minutes to go and five points in it, the Jaguares had another scrum 5m out and this time centre Damian de Allende scrummed at flank.
An almighty shove earned a penalty for the home team and sealed victory with flyhalf Damian Willemse landing the kick.
Despite first-half tries from centre De Allende and captain Siya Kolisi the Stormers would have been least pleased at the break.
Showing early season rustiness, they missed numerous scoring opportunities.
Some of the most frustrating included flank Cobus Wiese losing the ball over the line as he reached out to score and loosehead Steven Kitshoff dropping a clanger at a lineout 5m from the Jaguares line.
With a tour to Australasia starting next week, the Stormers will quickly have to sharpen their game because there was far too much largesse on offer.
Better opponents such as the Crusaders and Highlanders won't leave the Stormers unpunished for such poor finishing.
The Stormers lineout was messy, losing three on their own throw. Samuels, who was a late replacement for Bongi Mbonambi, struggled to find his jumpers from the outset.
Wiese was lively and hard on defence while No 8 Nizaam Carr carried effectively, providing a strong link with the backs while Willemse and Senatla showed some fine attacking touches.
The Jaguares were typically poorly disciplined and a yellow card was shown to fullback Joaquin Tuculet when he killed the ball with the Stormers on attack.
In all the Jaguares conceded 13 penalties to eight.
While Tuculet was off the field Kolisi, who had been almost anonymous up to that point, collected a pass at pace from a lineout on the Jaguares 22m line and burst through three tackles to score the second try of the match.
Debutant wing Raymond Rhule scored a fine solo try early in the second half to open a sizeable lead, but things fell apart after that...