The Sharks kept their Super Rugby Play off hopes alive after they edged out the Waratahs 26-21 in Durban.
Both teams scored two tries each and the difference came down to kicks with Patrick Lambie kicking two more of his kicks than Kurtley Beale.
The result means that the Waratahs will almost certainly need to beat the Bulls next week in Loftus if they want to keep their play off hopes alive.
The result also moves the Sharks above the Waratahs on the overall standings and pushes the Highlanders out of the top six.
The turning point in the match was thought to have come when the Waratahs were leading half way through the second half and Jean Deysel was shown a yellow card which reduced the Sharks to 14 men.
With an extra man the Waratahs extended their lead to 8 points with the resulting penalty but the Sharks dug deep and winger JP Pietersen scored a breakaway try to bring the Sharks to within a point.
Patrick Lambie kicked two further penalties to give the Sharks a vital victory.
Patrick Lambie scored 21points, among them a try, with the balance coming courtesy of a JP Pietersen try.
There were also two tries for the Australian side that came through Lachie Turner and Daniel Halangahu and earned them a bonus point, but that will be little consolation as they dropped to sixth place on the overall standings behind the Sharks.
It all came after a positive start for Chris Hickey's team, who took the lead after four minutes when Kurtley Beale slotted over a penalty.
Conrad Hoffmann then saved a certain try when he got the better of Ryan Cross in a straight race for the line after the midfielder found some space when he kicked forward a loose ball.
At that stage, the hosts were struggling to get into the game and another penalty in front of goal allowed Beale to again line up for goal, but this time he missed.
From the subsequent kick-off, the Sharks won a scrum and Lambie took a quick ball from Hoffmann at the base, before slicing his way through two defenders to touch down under the post.
The young flyhalf had no problem adding the extras, but errors continued to come almost at will for the home side - another one by Alistair Hargreaves, who failed to roll away, allowed Beale to cut the gap to one.
Lambie kept the scoreboard ticking over at the other end with back-to-back penalties, the second coming after impressive build-up play by veteran back Stefan Terblanche and his forwards.
Five minutes before the break, the Waratahs emphatically turned desperate defence into attack resulting in their opening try.
It came when they turned the ball over 10 metres out and spread it wide for Halangahu to run almost the length of the field, before offloading to Turner as he dived in on the left corner.
Beale missed the chance to draw his side level with the visitors trailing 11-13 at the break.
After the restart, some sloppiness from the Sharks saw them surrender the lead after another spell of ordinary rugby.
First, Lambie missed the chance to extend the lead when a long-range penalty faded narrowly wide, before Louis Ludik's clumsy knock-on brought back memories of last week's error-strewn performance again the Bulls.
From the subsequent scrum, Halangahu shrugged off at least four challenges to score under the post - this time the try converted by Beale.
Things went from bad to worse for the men in black with Jean Deysel then sent to the sin bin for a dangerous tackle on Tom Carter, an error that allowed Beale to send over another three points.
However, they were thrown a lifeline when Pietersen found a loose ball and ran 50 metres to score a converted try on the right.
With 15 minutes remaining, Lambie missed the chance to put his team back in front when he struck the post, but he but made amends moments later as John Plumtree's Sharks held on while Lambie found his kicking boots.
Final Score Sharks 26 Waratahs 21
Tries - P Lambie, JP Pietersen
Pen - P Lambie 4
Con - P Lambie 2
Cards - Jean Deysel (50th min) Yellow.
Tries - L Turner, D Halangahu
Pen - K Beale 3
Con - D Halangahu
Man of the match : JP Pietersen
Referee: Jonathan Kaplan (South Africa)
Assistant referees: Jaco Peyper (South Africa), Stefan Breytenbach (South Africa)
Television match official: Johann Meuwesen (South Africa)
Sharks :1. John Smit (Captain) , 2. Bismarck du Plessis , 3. Eugene van Staden , 4. Steven Sykes , 5. Alistair Hargreaves , 6. Jacques Botes , 7. Jean Deysel , 8. Keegan Daniel , 9. Conrad Hoffmann , 10. Patrick Lambie , 11. Lwazi Mvovo , 12. Meyer Bosman , 13. Stefan Terblanche , 14. JP Pietersen , 15. Louis Ludik
Replacements , 16. Tendai Mtawarira , 17. Wiehahn Herbst , 18. Gerhard Mostert , 19. Willem Alberts , 20. Charl McLeod , 21. Jacques-Louis Potgieter , 22. Riaan Swanepoel
Waratahs:15. Kurtley Beale , 14. Lachie Turner , 13. Ryan Cross , 12. Tom Carter , 11. Sosene Anesi , 10. Daniel Halangahu , 9. Luke Burgess , 8. Ben Mowen , 7. Chris Alcock , 6. Dave Dennis , 5. Sitaleki Timani , 4. Dean Mumm [c] , 3. Sekope Kepu , 2. Tatafu Polota-Nau , 1. Benn Robinson
Reserves , 16. John Ulugia , 17. Al Baxter , 18. Pat O 'Connor , 19. Hugh Perrett , 20. Brendan McKibbin , 21. Ben Batger , 22. Atieli Pakalani