The Scotland wing, who played for the Springboks’ Under-20 side, was named man of the match as he continued to excel on the international stage.
Not to be outdone, Josh Adams weighed in with a treble of his own as the tourists built more momentum in difficult circumstances. There were also tries from Bundee Aki and Louis Rees-Zammit as the Lions made it three wins in a row.
This could become known as the tour of adversity but so far Warren Gatland’s side have managed to cope with everything that has been thrown at them.
The opposition may not have been from the top drawer but the Lions coach will be satisfied with the manner of the victory given the prelude to the game.
The build-up was chaotic and necessitated a number of late changes to the team after PCR testing uncovered Covid-19 positive cases in one Lions player and one member of the management team. Another eight players were forced into isolation as close contacts, causing Gatland into a reshuffle.
The backs bore the brunt of the changes, with four new faces in the starting XV and no sign of attack coach Gregor Townsend inside Ellis Park.
Ali Price, the Scotland scrum-half who was not in the original 23, started the match in place of Gareth Davies. There were also late call-ups for Adams, who replaced Liam Williams at full-back, Rees-Zammit, who stepped in for Anthony Watson on the right wing, and Owen Farrell, who came in for Dan Biggar at stand-off.
Such was the improvised nature of the preparations, Farrell played without a number on his jersey while Rees-Zammit wore No 10. It was all a little strange.
The problems were more pronounced on the replacements’ bench where there was a seven-one forwards to backs split, leaving Finn Russell to cover positions nine to 15. The Scotland stand-off is supremely gifted but even this was surely asking too much.
The tourists’ ability to improvise and adapt was being put to the test but they delivered an emphatic answer with two tries inside the first six minutes.
Adams got the ball rolling with his sixth try in three Lions games, cashing in after good offloading from first Farrell and then Rees-Zammit.
Van der Merwe increased the lead following a looping pass from Sam Simmonds after good work by Adam Beard. Farrell converted both and the Lions were 14 points to the good before the Sharks had had a chance to catch breath.
Their cause wasn’t helped by a yellow card for winger Wener Kok and the Lions were starting to enjoy themselves.
Luke Cowan-Dickie thought he had scored the Lions’ third try but he failed to ground the ball. Farrell tried a more subtle way of breaching the Sharks defence, putting through a delicate grubber for Rees-Zammit to run on to but the Wales wing was too quick for his own good and fumbled the ball as he stooped to pick up.
Farrell wasn’t dissuaded and when he chipped through again a few minutes later, van der Merwe galloped down the left flank, dribbled the ball over the line and fell on it for a neat finish. Farrell’s conversion attempt went narrowly wide but the Lions increased their lead just before the half-time hooter, Aki powering over from close range. This time the conversion from Farrell was good and the Lions went into the changing rooms with a 26-0 lead.
The Sharks were deprived of most of their first-choice forwards who were away with the Springboks, but they showed plenty of guts and stunned the Lions with a try five minutes into the second half.
Kok sparked a fine move down the right wing and flanker James Venter finished the move, with Curwin Bosch converting.
The Lions decided it was time to freshen things up and Rory Sutherland, Tadhg Furlong and Russell entered the fray in place of Mako Vunipola, Zander Fagerson and Farrell, respectively.
It had the desired effect as the tourists bit back with two quick tries. Adams got his second score of the game when he capitalised on a couple of Sharks errors, hacking the ball on when a Sharks turnover went awry and Thaakir Abrahams failed to clear the danger.
The full-back then turned creator, taking the ball into a tackle before offloading for Rees-Zammit to streak clear. Russell, who had taken over kicking duties from Farrell, converted both.
There was still time for van der Merwe and Adams to bump up their try stats and both managed to finish the game with hat-tricks, testament to their finishing ability.
The Scotland wing was first to bag a treble after good work by Sutherland. Adams then finished off a lovely side-to-side backs move to set the seal on a solid win.
Russell, immaculate off the tee, added another two conversions.
Scorers. Sharks: Tries: Venter. Con: Bosch.
Lions: Tries: Van der Merwe 3, Adams 3, Aki, Rees-Zammit. Cons: Farrell 3, Russell 4.
Sharks: Libbok; Kok, Ward, Louw, Abrahams; Bosch, Henrikse; Mona, Mbatha, K. Mchunu, van Heerden, Andrews, J. Venter, Bholi, Buthelezi.
Replacements: van Vuuren, N. Mchunu, Herbst, van der Mescht, Hugo, Richardson, Williams, Volmink.
British & Irish Lions:Adams; Rees-Zammit, Daly, Aki, van der Merwe; Farrell (Russell 51), Price; Vunipola (Sutherland 51), Cowan-Dickie, Fagerson (Furlong 51), Henderson, Beard, Navidi (H. Watson), Curry, Simmonds.
Replacements: Owens, Itoje, Conan, Faletau.
Referee: Jaco Peyper (South Africa)