The Blitzboks, boosted by four tries from winger, Siviwe Soyizwapi, totally outplayed their Irish opponents at AT&T Park, with their opponents scoring their only points in the last play of the match.
The defending champion Black Ferns topped 100 total points scored after winning their first two matches 57-0 and 45-0 against Mexico and Ireland respectively.
That was 3min 25sec out from halftime.
Shortly afterwards, Geduld sparked some magic when he intercepted a pass and showed dazzling feet to set Soyizwapi up for his second.
Dardis was again instrumental in Ireland's next attack when he sucked in two defenders before releasing Jimmy O'Brien who expertly dodged through two tackles before running the length of the field for Ireland's second try which Dardis converted.
Coach Neil Powell's Blitzboks will now take on Scotland in their quarter-final clash.
Seven women's players from five countries will enter the pitch in San Francisco to make their third Rugby World Cup Sevens appearance: Beatrice Muhlbauer (Brazil), Claire Allan and Heather Fisher (England), Fanny Horta (France), Zenay Jordaan (South Africa) and Marina Bravo and Barbara Pla (Spain).
The Commonwealth Games gold medalists kept a clean sheet in their day one thumpings of Mexico and Ireland, before a gutsy come-from-behind semifinal victory over a fiery US team, buoyed on by a loud home support base at the AT&T Park baseball stadium.
"When a Fijian team gets that sort of momentum they're very hard to beat", said Fiji's satisfied coach Gareth Baber.
"We awarded our most prestigious sevens event to the United States of America because we know that it is much more than a nation with simply rugby potential, but a nation with a growing, thriving and engaged rugby audience".
From turnover possession, Russian Federation captain Alena Mikhaltsova shrugged off a defender to score against the run of play.
France then edged Canada 24-19 in a see-saw affair that had seemed destined for extra-time before Coralie Bertrand, the rookie of the year on the 2018 World Sevens Series, scored to secure Les Bleus a maiden RWC Sevens semifinal berth.