The British and Irish Lions pulled through their toughest test so far as they overcame a committed Sharks side and their own errors to claim victory.
But scrum-half Jaden Hendrikse's 46th-minute red card for a cheap-shot elbow to Liam Williams' head swung the game.
The Lions piled on the points with wing Anthony Watson scoring two of 11 tries.
Flanker Tadhg Beirne and hooker Jamie George, captaining the side, also crossed twice with close-range efforts.
The Lions polished up the scoreline as they ran in seven second-half tries against the depleted hosts, but Warren Gatland will know his side helped keep their youthful and physical opposition in the contest in a slack first-half display.
Three of the Durban side's four first-half tries came from individual errors from the Lions.
Full-back Anthony Volmink strolled in after Elliot Daly, impressive so far on the tour, spilled a ball under little pressure and then capitalised when Dan Biggar's pass to Duhan van der Merwe went to ground.
Hendrikse intercepted a sloppy pass from opposite number nine Gareth Davies to run the length of the field and make it 26-19 to the Sharks within sight of half-time.
The Lions seemed to be feeling the effects of a week severely disrupted by a Covid outbreak in their camp, but were handed a crucial advantage when the lively Hendrikse boiled over in a touchline skirmish.
The scrum-half needlessly dived in as Williams was dragged out of play, planting his elbow on the Wales full-back's head.
It was more nuisance than violence, but English referee Wayne Barnes had no choice but to show red - and all but end the game as a contest.
Van der Merwe strengthens Test case with powerful performance
Van der Merwe, a former South Africa Under-20 international who made his Scotland debut in October, has been the target of some needle.
A tweeted Springbok video welcoming the Lions to South Africa in various languages, included a jibe suggesting he could translate the Afrikaans section. The Ellis Park stadium announcer greeted his three tries against the Sharks on Wednesday in Afrikaans as well.
But the 26-year-old shows no sign of being thrown off his game.
He beat more defenders than any other Lions player (13) combining pace with power, and looked secure under the high ball as well.
It was his deft offload that also set up Chris Harris for the opening score on four minutes.
Anthony Watson, who made his first start of the tour on the opposite wing, has genuine competition if he is to retain the Test shirt he made his own in 2017.
Man of the match - Elliot Daly
Line-ups
Sharks: Volmink; Potgieter, Kok, Koster, Abrahams; Cronje, Hendrikse; N Mchunu, Van Vuuren, Herbst, Roets, Hugo, Richardson, Gumede, Buthelezi (capt)
Replacements: Jooste, Majola, K Mchunu, Bholi, Labushagne, Wright, Chamberlain, Ward, Adriaanse, Jonker, Bosch
British and Irish Lions: L Williams, A Watson, Daly, Harris, Van der Merwe; Biggar, Davies; Sutherland, George (capt), Furlong, Lawes, Hill, Beirne, H Watson, Conan.
Replacements: Owens, Jones, Sinckler, Beard, Simmonds, Curry, Murray, Aki.