United Rugby Championship

A third-minute score from Harold Vorster helped the Bulls into a 7-3 lead at half-time but Evan Roos replied early in the second period.

Andre-Hugo Venter then added a second try for the hosts shortly after Bulls centre Cornal Hendricks was sin-binned.

A late drop-goal from fly-half Manie Libbok sealed the result.

The competition was previously known as the Pro14 but was rebranded for the 2021-22 campaign following the introduction of four sides from South Africa.

The club confirmed one of the cases is suspected to be the Omicron variant that sparked travel restrictions on flights from South Africa to the UK.

A Cardiff statement said: "PCR tests undertaken last night have returned two positive results."

However, Welsh rivals Scarlets are on the flight both teams were due to take.

Irish side Munster also have a positive Covid case and, like Cardiff, must remain in isolation in South Africa.

Cardiff's playing and coaching staff have "returned to their hotel to isolate".