Despite failing to play their best rugby in Christchurch on Saturday, the defending champion Crusaders were always in control in their quarter-final.
By snaring a 13th successive win they took a step closer to their ninth title.
However, a stiffer challenge awaits in Christchurch next week against a Hurricanes side who showed signs of returning to their best in Friday's quarter- final defeat of the Chiefs.
The Crusaders will want to be better, spending chunks of the match inside their half, not helped by a faltering lineout display.
However, their defence was able to cope with most of what the Durban-based visitors threw at them, aside from when winger Kobus van Wyk scored following an extended period of Sharks dominance.
It left the Crusaders 16-7 ahead at halftime before a try soon after the break to Matt Todd boosted their buffer.
Reserves Braydon Ennor and Pete Samu bagged late tries as the Crusaders lived up to widespread predictions they'd win comfortably.
Ennor's introduction came following the departure of winger Seta Tamanivalu, who was knocked out momentarily when trying to stop van Wyk's try.
Earlier, the Crusaders suggested they'd romp to victory when halfback Bryn Hall and fullback David Havili crossed inside the first 12 minutes to put their team 13-0 up.
No South African franchise has ever won a finals game in New Zealand in 13 attempts.
Prop Tendai Mtawarira played his 150th game for the Sharks, who qualified in eighth spot, heading off the Melbourne Rebels on points differential.