The Brumbies and the Hurricanes recorded contrasting victories on Saturday ahead of home quarter-finals.
There was late drama in both Super Rugby matches on Friday, with Scott Higginbotham the hero for the Reds in their win over the Blues.
The Brumbies have been dealt another blow, with confirmation that Henry Speight will leave the club to join the Reds at the end of 2019.
A 19-13 defeat to the Chiefs has ruined the Reds' hopes of reaching the Super Rugby finals, while the Brumbies beat the Bulls on Friday.
The Blues kept their Super Rugby play-off hopes alive, while the Reds were beaten in a tense encounter with the Waratahs.
Two yellow cards proved costly as the Reds were beaten by the Rebels, while the Hurricanes picked off the Blues at Eden Park.
The Sharks were leading the Super Rugby champions when the final hooter sounded, but Mitch Hunt's late intervention denied them.
A second-half fightback was needed for the Hurricanes to avoid a shock defeat to the Sunwolves in Super Rugby.
After captaining the Reds, Australia and Harlequins, James Horwill is preparing for the final weeks of his career.
The Sharks gave another demonstration of their inconsistent at Kings Park, where the Jaguares ran riot with a seven-try drubbing.