Superb performances by Sharks captain Keegan Daniel, hooker Craig Burden and fly-half Patrick Lambie helped their side to a 29-23 victory over an error-ridden Blues team at Eden Park.
Steven Sykes and Tim Whitehead also touched down in addition to Burden and Daniel, with Lambie kicking the rest of their points.
Tony Woodcock and Benson Stanley were the try-scorers for the Blues, while Gareth Anscombe contributed 13 points with the boot.
The NSW Waratahs survived a spirited Western Force fightback to get their play-off hopes back on track with a 23-18 success.
NSW were desperate for victory given they had won just two of their first six matches, and they came through at nib Stadium despite blowing a 14-point lead in just 22 minutes.
Dave Dennis' second-half try gave the Waratahs a 17-3 advantage after 42 minutes but five-pointers in quick succession from Brett Sheehan and Alfie Mafi, as well as the impressive kicking of David Harvey, saw the Force go ahead with 16 minutes left.
But the visitors responded through the boot of Berrick Barnes, who slotted two penalties in the final 15 minutes to secure a hard-fought victory.
Tom Kingston also scored a try for NSW to help them move to the top of the Australian conference, at least temporarily, while Brendan McKibbin nailed one penalty and two conversions.