Orlando Pirates edged fellow giants Mamelodi Sundowns while Bloemfontein Celtic slumped at home and Maritzburg United axed German coach Ernst Middendorp in South African Cup drama on Saturday.
Midfielder Tlou Segolela scored the only goal of the Soweto showdown between league leaders Pirates and third-place Sundowns after 59 minutes and team-mate Happy Jele was sent off for a second caution almost immediately.
A solitary goal also settled the clash of Celtic -- unbeaten at home this season in 12 league games -- and Platimum Stars with Namibian Henrico Botes snatching the winner midway through the second half.
Volatile former Bundesliga coach Middendorp failed to lift Maritzburg away from the relegation zone this season and a 3-0 home drubbing by Moroka Swallows Friday in another first round tie proved the final straw.
Ajax Cape Town, just one point behind Pirates ahead of a top-of-the-table league clash next Wednesday, were another Premiership club to be eliminated as they fell 2-1 at combative Free State Stars.
Relegation-bound Mpumalanga Black Aces temporarily put their league woes aside to hit three late goals and oust second-tier Hanover Park 4-2 and Vasco da Gama and third division BTX Liverpool also won to make the last-16 draw.
Pirates striker Katlego Mashego was twice foiled by the woodwork during the first half and had a penalty saved by Wayne Sandilands just before Segolela controlled a deep cross with his chest and slammed the ball into the net.
Sundowns could not take advantage of their numerical superiority as in-form striker Katlego Mphela miscued a rebound with the goal at his mercy 13 minutes from full-time.
Celtic have been unbeaten since losing away to Pirates three months ago in the Premiership and seemed a good bet to go far in the competition won by unfashionable Wits University last season.
But they were undone at their Seisa Ramabodu fortress by midfielder Botes, who unleashed a fierce low shot that flew across Cameroonian goalkeeper Patrick Tignyemb and into the far corner of the net.
Free State scored twice within seven minutes during the second half through Aleni Lebyane and Ayanda Gcaba and all Ajax could muster in reply was a 78th-minute goal from Zimbabwean Willard Katsande.
There are a further five fixtures Sunday with record 12-time Cup winners Kaizer Chiefs sure to be wary of facing lower league Nathi Lions away after being eliminated by first division clubs in the previous two seasons.