The Sharks extended their winning streak over the Blues to eight straight matches with a 23-29 bonus point victory in Auckland.
The Blues' sixth loss in seven games adds to the pressure on coach Pat Lam, who broke down in tears this week recounting how racist "fans" had blamed the team's worst ever start to a Super rugby season on his Samoan heritage.
The result maintained the Sharks record as a bogey team for the Blues, who have not defeated the South Africans since 2005 and remain rooted to the bottom of the New Zealand conference after the loss.
It was a deserved win for the Sharks, who scored four tries to two and maintained their attacking edge after the Blues briefly took the lead early in the second half.
After beig well beaten last week 42-18 by the Hurricanes the Sharks sorted out their defence as the Blues threw everything into attack late in the game.
Handling errors and simple mistakes again proved the Blues' downfall as the Auckland side conceded two early intercept tries to give the Sharks a flying start.
Sharks captain Keegan Daniel set up the opening try in the third minute, intercepting a loose pass from Benson Stanley and running half the length of the field before being brought down just short of the line.
Lock Steven Sykes roared up in support and bulldozed his way past an ineffectual Blues defence for the five-pointer.
Stanley almost made amends five minutes later, releasing Ma'a Nonu for a driving run but the attack broke down after a knock on from Gareth Anscombe.
Fly-half Pat Lambie extended the Sharks' lead with a penalty after 15 minutes, then another Blues mistake gifted the South Africans a second intercept try two minutes later.
Chris Lowrey passed the ball straight to Sharks hooker Craig Burden, who set off from inside his own half, outpacing Rudi Wulf for the try, with Lambie adding the conversion to make it 15-0.
The Blues made it onto the scoreboard through an Anscombe penalty and finally began to exert some pressure late in the opening half as their lineout, another problem area this year, began to click.
The hard work paid off when the Blues won a scrum against the feed, with prop Tony Woodcock forcing his way past two defenders for a try seven minutes from the break.
Anscombe converted the try and potted a late drop goal to narrow the Sharks' lead to 15-13 at half-time.
The Blues maintained their momentum after the re-start, taking the lead when Stanley gathered a loose pass from the base of the Sharks' scrum and touched down between the posts, ensuring an easy conversion for Anscombe.
But the Sharks hit back with two quick tries, the first from Daniel, who darted past two defenders before crossing the line.
The second came after Lambie made a superb line break then offloaded to Tim Whitehead, who juggled the ball while running at full tilt then steadied to score a bonus point try to make it 29-20.
Anscombe cut the deficit to six points with a penalty 15 minutes from time but the Sharks defence proved up to the challenge as the clock wound down, giving then their fourth win in eight games.
Final Score Blues 23 (13) Sharks 29 (15)
Tries - T. Woodcock, B. Stanley
Pen - G. Anscombe 2
Con - G. Anscombe 2
Drop - G. Anscombe
Tries - S. Sykes, C. Burden, K. Daniel, T. Whitehead
Pen - P. Lambie
Con - P. Lambie 3
Referee: Steve Walsh
Assistant Ref 1: Jonathon White
Assistant Ref 2: Nick Briant
TMO: Bryce Lawrence
1. Tony Woodcock, 2. Keven Mealamu (c), 3. Charlie Faumuina, 4. Liaki Moli, 5. Filo Paulo, 6. Luke Braid, 7. Dan Braid, 8. Chris Lowrey, 9. Alby Mathewson, 10. Gareth Anscombe, 11. Rene Ranger, 12. Ma’a Nonu, 13. Benson Stanley, 14. Hadleigh Parkes, 15. Rudi Wulf.
Replacements: 16. Tom McCartney, 17. Tevita Mailau, 18. Ali Williams, 19. Peter Saili, 20. Piri Weepu, 21. Michael Hobbs, 22. George Moala.
1. Dale Chadwick , 2. Craig Burden , 3. Jannie du Plessis , 4. Steven Sykes , 5. Anton Bresler , 6. Marcell Coetzee , 7. Jean Deysel , 8. Keegan Daniel (Captain) , 9. Charl McLeod , 10. Patrick Lambie , 11. Lwazi Mvovo , 12. Tim Whitehead , 13. JP Pietersen , 14. Louis Ludik , 15. Riaan Viljoen
Replacements: 16. Kyle Cooper , 17. Wiehahn Herbst , 18. Jandre Marais , 19. Willem Albert , 20. Jacques Botes , 21. Meyer Bosman , 22. Frederic Michalak.