The Brumbies have defeated the Stormers 39-19 in Cape Town to book a Super Rugby semi-final against top qualifiers the Hurricanes next weekend, but the victory was soured by a red card to wing Henry Speight.
Speight is in doubt for the clash in Wellington on Saturday after appearing to tip Stormers centre Juan de Jongh onto his head with around six minutes remaining in the match.
The Brumbies went down to 13 men with five minutes remaining when Scott Fardy was sin-binned for a professional foul, but the visitors still managed to score a try as fullback Jesse Mogg crashed over one minute from fulltime.
The Speight card spoiled a great performance for the Brumbies early this morning with the Canberra side outscoring the South African conference winners six tries to one.
Brumbies winger Joe Tomane set the game up for Stephen Larkham's side with a sensational hat-trick of tries in the first half, his opening five-pointer coming after just four minutes.
The Stormers lacked punch at the breakdown without Duane Vermeulen and Schalk Burger, who failed a late fitness test, and the Brumbies monstered their hosts at the breakdown with David Pocock prominent.
The visitors led 24-6 at halftime after prop Scott Sio scored a crucial try just before the break.
The Stormers fought back early in the second half with speedy fullback Cheslin Kolbe intercepting a Matt Toomua pass to run over 60 metres to score a converted try to make it 24-13.
The home side edged three points closer minutes later when sharp-shooting No.10 Demetri Catrakilis who slotted his third penalty goal of the match to make it 24-16.
Christian Lealiifano steadied things for the Brumbies after the early Stormers' onslaught with a penalty goal to make it 27-16.
Catrakilis nailed his fourth penalty on 61 minutes and it was 27-19 before No.8 Ita Vaea forced his way over from close range to score a converted try for the Brumbies.
Next weekend's semi-finals will feature two battles between Australian and New Zealand sides as the defending champion NSW Waratahs host the Highlanders who beat the Chiefs 24-14 in Dunedin last night.