The Crusaders ended the Sharks' reign as the only unbeaten Super Rugby side with a 19-14 win in Durban.
Skipper Kieran Read got the crucial try for Todd Blackadder's side by crashing over after 15 phases of patient rugby in the 71st minute.
Prior to that it was tough to call as Lwazi Mvovo's brace for the Sharks, both converted by Joe Pietersen, was cancelled out by scores from David Havili, converted by Richie Mo'unga, and Nemani Nadolo.
Both sides thought they had stolen the initiative in the second half only to be frustrated by the TMO, with Johnny McNicholl's effort scrubbed off for a foot in touch while Willie le Roux's break for the Sharks did not count because he was ahead of the kicker.
Read stepped up to get the Crusaders over the line in their first away match of the campaign, with Nadolo adding the conversion, and the hosts were unable to find an answer.