Struggling Queensland Reds face an early season must-win Super Rugby game while Australian conference pacesetters Melbourne will look to finally break their South African drought.
The 3-0 Rebels are one of just two unbeaten teams after a rousing come from behind 29-26 home win over the Brumbies on Friday.
The Reds are 0-3 and bottom of the Australian conference after their 28-17 loss to the NSW Waratahs on Saturday and are just one of two teams yet to register a win.
They desperately need to kickstart their season next Saturday when they play the Sunwolves, who are the team immediately above them in the conference.
"With the work we did pre-season, it felt like there's been growth in the group, tonight was really disappointing," Reds coach Brad Thorn said.
"(But) you do have those games."
While the Reds have been competitive without winning games, some of their discards continue to prosper.
Five-eighth Quade Cooper set up two tries for the Rebels, while centre Karmichael Hunt turned in another solid performance for the Tahs.
The major talking point at the SCG was the state of the surface with the ground staff forced onto the ground for repairs after each scrum, with the surface churned up.
Melbourne overcame a 19-3 halftime deficit and having two men sin-binned in the first 40 minutes to beat the Brumbies at AAMI Park on Friday night.
Wallabies back Jack Maddocks scored two tries in the second-half fightback, as Melbourne preserved their perfect start to the season.
The Rebels have never won in 15 matches in South Africa, where they will play their next two games.
They face the Lions, the losing finalists in each of the past three seasons, and then the Sharks, with both teams having a 2-2 record this season.
Melbourne could lose top spot if they fall to the Lions without getting a point and the Waratahs win next Friday in Canberra against the Brumbies, who need a victory to stay in touch with the top two in the conference,
Outside of Australia, the Crusaders and the Bulls are making the running in the New Zealand and African conferences respectively.
The two-times defending champions Crusaders chalked up a 19th successive win, smashing the Chiefs 57-28 in Christchurch.
Elsewhere in New Zealand, All Blacks five-eighth Beauden Barrett kicked a penalty after the hooter to give the Hurricanes a 25-22 win over the Highlanders in Wellington and Blues winger winger Rieko Ioane scored all four of his team's tries as they got their maiden victory for the season in a 28-20 triumph over the Sunwolves in Auckland.
Springboks five-eighth Handre Pollard scored 22 points as the Bulls knocked the Sharks off the top of the African conference with a 37-14 win over that side in Pretoria, while the Lions beat the Jaguares 47-39 in a 13-try extravaganza in Johannesburg.
