The Blue and Blacks, twice runners-up in the Celtic League before the introduction of play-offs, are in new territory.
The club have enjoyed knockout success when winning the Challenge Cup in 2010 and 2018, while they also lifted the 2009 Anglo-Welsh Cup.
This is a first taste of URC play-off pressure and they face a Stormers side who have been knocked out in the quarter-finals for the past two seasons, although both losses were on their travels to Glasgow.
Cardiff’s fine form on their plastic pitch at the Arms Park – eight wins from nine games in the URC – earned qualification, but they now travel to one of the league’s toughest venues.
John Dobson’s side have lost just eight home league fixtures over five seasons, although Connacht provided reason to believe when they upset the odds in round 15.
“The younger guys had no fear, they just ripped into it,” said head coach Stuart Lancaster, who was without Bundee Aki, Finlay Bealham, Mack Hansen and Denis Buckley.
Ospreys also won 27-21 in Cape Town in April 2024, but Stormers have won five of six home play-off games, with the only disappointment coming against Munster in the 2023 Grand Final.
So, arguably Cardiff are bigger underdogs at DHL Stadium than Lions at Leinster, Munster at Bulls or Connacht at Glasgow this weekend.