The Sharks bungled a 20-point half-time lead to lose 36-30 against Connacht in their United Rugby Championship clash at Dexcom Stadium.
The Stormers allowed a first-half lead to slip as they fell to a 37-24 defeat against the Ospreys in an exciting clash in Bridgend on Saturday night.
The Bulls opened their United Rugby Championship (URC) campaign with a hard-fought 22-16 victory against Edinburgh at Loftus on Saturday.
The Lions got their URC campaign to a perfect start as they claimed a 35-22 bonus-point victory over Ulster at Ellis Park.
Centre Dan du Plessis will captain the Stormers in their United Rugby Championship opener against Ospreys at Dunraven Brewery Field in Bridgend on Saturday.
A 29-man Stormers squad left Cape Town on Tuesday for a three-match United Rugby Championship tour which will see them visit Wales, Italy and Scotland.