The unerring accuracy of fly-half Johan Goosen fired Vodacom Bulls to a sound win in Pool 1 of the Investec Champions Cup, defeating Saracens 27-16 in what turned out to be a painful afternoon for the visitors.
Centre David Kriel and forward Janko Swanepoel crossed at either end of the first half with Goosen converting both times as well as adding two penalties.
Owen Farrell also kicked two penalties, getting Sarries on the scoresheet, but they suffered two yellow cards in the space of 12 minutes, first to full back Alex Goode on 26 minutes, and then second row Maro Itoje on 38 minutes.
Wing Canan Moodie put Vodacom Bulls further in front at the start of the second half, with Goosen nailing the conversion again.
Things only got harder for the travelling side when Number 8 Billy Vunipola was sent off on 51 minutes after flying into a ruck.
They had two glimmers of consolation when centre Elliot Daly picked up a pass from Goode and crossed in the corner on the hour, followed by replacement Theo McFarland adding a second try ten minutes later, but Farrell missed both conversions as Vodacom Bulls claimed an opening win.
They will now face Lyon away from home in their second match, with Saracens hosting Connacht Rugby.