The Melbourne Rebels threw everything at the Stormers but were unable to send their retiring skipper Stirling Mortlock out a winner, losing 26-21 in Cape Town.
The lowly Rebels got to within two points in the final 10 minutes against the Super Rugby front-runners but the home side showed their class and super-boot Peter Grant kicked a final penalty to cap the win.
With only two losses for the home and away season, the Stormers earned a home semi-final next weekend and home final should they win.
Melbourne, who finished the season 13th, were out to post their first ever win in South Africa after going so close against the Lions in Johannesburg last round.
Again, they were forced to settle for a narrow loss.
"The intent was excellent but our execution at times let us down," said Rebels coach Damien Hill.
"There was some great play there; some very good elements of our attack and very good elements of our defence in particular.
"There was just one or two opportunities in attack and a couple of lapses in defence which were the difference."
Melbourne got better as the game went on, fighting back from 16-0 at half-time.
They scored two tries within three minutes - through prop Rodney Blake and halfback Nick Phipps - to get put the Stormers on notice at 16-14.
After the Stormers responded with centre Juan De Jongh scoring his second try of the match, the Rebels got a sniff of victory when Australia aspirant Cooper Vuna, who came off the bench, scored with eight minutes on the clock.
He combined with James Hilgendorf and replacement halfback Nick Stirzacker, playing only his second match, to touch down.
Hill thought his side outshone the Stormers in the second half.
"It was a poor start and we couldn't get the better of the whistle but you can't be anything but pleased with the effort the boys put in," he said.
Former Wallabies skipper Mortlock, 35, announced last month he planned to hang up his boots at the end of the Super season and the Rebels were also farewelling a number of other players.
Lock Al Campbell is also retiring while veteran fullback Julian Huxley is headed to France and centre Mark Gerrard to Japan.
