Rivaldo Coetzee came in for Kermit Erasmus while Ricardo Goss was got the nod ahead of Reyaad Piterse in goals as the Brazilians switched formation from their 2-0 victory over Chippa United.
Sundowns had the first opportunity with just 30 seconds gone on the clock. Siphelele Mkhulise played the ball into the feet of Peter Shalulile in the box and the Namibian striker flicked the ball around the corner for Themba Zwane, who tried to curl one with the outside of his foot but ended up slicing the effort wide.
The visitors took the lead against the run of play. Rivaldo Coetzee played a sloppy pass deep inside his own half and Ashley du Preez seized on the ball before going one-on-one with Brazilians keeper Denis Onyango and slotting it into the back of the net.
The equaliser came just four minutes later. Lebohang Maboe played a lovely ball over the top for Shalulile who made an excellent run in behind before flicking the ball over the onrushing Stephens and running the ball into the empty net.
With 10 minutes left of the half, Gaston Sirino found a pocket of space on the edge of the box and used Robyn Johannes as a shield, curling the ball around the Stellies defender but it grazed Stephens' left-hand upright. Meanwhile, Lakay struck the upright with a free-kick with the final action of the first half.
Gaston Sirino beat the Stellies' offside trap after67 minutes as he attempted to latch onto Ricardo Nascimento's long ball but his touch was a little bit too heavy as Stephens dealt with the danger. Five minutes later, Zwane played the one-two with and crossed into the box for Shalulile but his effort was well saved at close range by the Stellies shot-stopper.
Stephens came to the rescue once again soon afterwards when Sirino was played in by and curled an effort to Stephens' left-hand side but the keeper dived smartly to make the save.
In the first minute of stoppage time, Lesedi Kapinga teed up Sirino on the edge of the box and although the Uruguayan slipped while taking the shot he directed the effort into the bottom right-hand corner.
But in yet another dramatic turn to the game, the two Stellies substitutes combined to wonderful effect as Junior Mendeta nutmegged his marker out on the right-hand touchline and squared the ball back into the box for Phathutshedzo Nange.
Maboe had been impressive all night and created the opportunity for Shalulile with a cut-back into the box but the Downs striker hit the bar before the ball fell to Maboe but he was flagged for offside.
Just when it looked as if the game was heading for penalties Kapinga teed up Shalulile, who produced an exquisite finish into the bottom right-hand corner to decide a thrilling encounter.
Polokwane City 2-0 Steenberg United