A third goal in as many games from youngster Ndumiso Mabena and an equaliser from Cosmos captain Thapelo Tshilo had left the score locked at 1-1 before Mabalane was able to find the winning strike in the 71st minute.
Neither side was able to really hit their stride in the first half, though Cosmos created more half-chances than their visitors.
The front three of Gassousou Diarra, Ayo Oluwafemi and Norman Smith provided a fair amount of movement and invention up front for the home team and they posed more of an attacking threat despite seeing less of the ball.
Ezenkosi really should have taken the lead just past the half hour mark when Diarra skipped through the Pirates backline but chose to try and square the ball across the penalty area when he had the time and space to get away a shot.
Pirates, for their part, had plenty of possession but hardly worried Cosmos’ defence. The Buccaneers’ only real threat came down the left flank where Bennet Chenene looked lively.
Pirates’ Dikgang Mabalane, who had a blinder of a game in their first round win over Bloemfontein Celtic, was completely neutralised by Tshepo Moloto. The youngster, who usually plays a striker, was deployed at left-back purely to match ‘Terminator’s’ devastating speed.
Buccaneers coach Ruud Krol generally leaves it late to make substitutions but opted for a change in the interval, withdrawing defensive midfielder Mlungisi Mdluli and sending on the more offensively-minded Denis Masina.
The more attacking approach paid immediate dividends, with Ndumiso Mabena breaking the deadlock three minutes into the second half. Thapelo Tshilo failed to clear a Mabalane cross and the ball fell for Mabena, who struck a low shot past Avril Phali’s left hand and found the bottom corner of the net.
Tshilo, who was culpable for Pirates’ goal, more than redeemed himself by scoring a stunning equaliser in the 54th minute. The lanky central defender found the back of the net from a free kick more than 30 metres from goal, driving home a low shot that appeared to take a slight deflection on its way through.
Just under ten minutes later Pirates were lucky not to be reduced to ten men when Rooi Mahamutsa tripped Smith from behind after the striker had got ahead of the Buccaneers defender and looked to have a clean run on goal. Referee Jerome Damon failed to even award a free kick.
Though he was wrapped up in the first half by Moloto, Mabalane was gradually beginning to have more influence on the game and he duly restored Pirates’ lead with just under 20 minutes to play.
Cosmos again failed to clear their lines effectively and were punished when Mabalane hit a shot from the edge of the penalty area that skipped through a crowd of players and found the bottom corner of Phali’s net.
Any hopes Ezenkosi had of finding a late equaliser were all but eliminated when Tshilo was dismissed for picking up a completely unnecessary second yellow card.