The Stormers secured a home quarter-final after claiming a deserved 22-3 victory over the Western Force in Perth.
The match was played in atrocious weather conditions with heavy rain restricting play mostly to the forwards -especially during the first half - but when the ball was played to the backs, however, the Stormers were the more enterprising side and they outscored their hosts three tries to zero.
The result means the Stormers will finish at the top of the Africa One Conference table with one match to play still while the Force are at the bottom of the Australian Conference standings.
The big talking point in the opening half was the yellow card issued to Daniel du Plessis in the 10th minute by referee Mike Fraser, in conjunction with the TMO, Peter Marshall.
Du Plessis was knocked out cold by Marcel Brache, who landed awkwardly while fielding a high ball but, after watching television replays, the two match officials bizarrely decided to give the Stormers centre his marching orders for his role in the incident.
Five minutes earlier, Jono Lance had given the Force the lead via the kicking tee but that would be the only time the home side held the lead in this encounter as the Stormers soon took control of proceedings.
The rest of the half saw plenty of territorial kicking from both sides and there were few point-scoring opportunities as both teams committed several handling errors on attack in the difficult conditions.
The match came alive just before half-time when the visitors scored two tries in quick succesion.
The first one came after Eben Etzebeth ran onto a pass from Nic Groom in the Force's 22 and off-loaded to Jaco Taute, who did well to draw in a defender before passing to Kobus van Wyk who crossed for the opening try.
The visitors continued to attack and on the stroke of half-time Siya Kolisi powered through a tackle for the second five-pointer which gave his side a 15-3 lead at half-time.
The men from the Cape continued to dominate in the second period although they had to wait until the 56th minute to secure their bonus-point try. Van Wyk rounding off after Taute laid the groundwork after launching a counter-attack from close to the half-way line.
The rest of the match was an attritional affair as the Stormers tried to hammer home their advantage and the Force gave their all to at least narrow the gap but several unforced errors, from both sides, meant that neither side could add to their points tally.
For Western Force:
Tries: Van Wyk 2, Kolisi
Cons: JL du Plessis 2
Pen: JL du Plessis
Yellow Card: D du Plessis
Western Force: 15 Dane Haylett-Petty, 14 Marcel Brache, 13 Ben Tapuai, 12 Kyle Godwin, 11 Luke Morahan (c), 10 Jono Lance, 9 Ryan Louwrens, 8 Angus Cottrell, 7 Chris Alcock, 6 Richard Hardwick, 5 Rory Walton, 4 Ross Haylett-Petty, 3 Guy Millar, 2 Harry Scoble, 1 Pek Cowan
Replacements: 16 Anaru Rangi, 17 Francois van Wyk, 18 Jermaine Ainsley, 19 Matt Philip, 20 Brynard Stander, 21 Ian Prior, 22 Peter Grant, 23 Semisi Masirewa
Stormers: 15 Jaco Taute, 14 Kobus van Wyk, 13 Daniel du Plessis, 12 Damian de Allende, 11 Leolin Zas, 10 Jean-Luc du Plessis, 9 Nic Groom, 8 Schalk Burger (c), 7 Siya Kolisi, 6 Sikhumbuzo Notshe, 5 Pieter-Steph du Toit, 4 Eben Etzebeth, 3 Vincent Koch, 2 Bongi Mbonambi, 1 Alistair Vermaak
Replacements: 16 Scarra Ntubeni, 17 JP Smith, 18 Wilco Louw, 19 JD Schickerling, 20 Rynhardt Elstadt, 21 Louis Schreuder, 22 Huw Jones, 23 Scott van Breda
Referee: Mike Fraser
Assistant Referees: Graham Cooper, Michael Hogan
TMO: Peter Marshall