Chiefs were far from their fluent best on the night, with the Limpopo side deserved winners after they scored first through Morgan Shivambu before netting a late winner through Roggert Nyundu after Willard Katsande had briefly put the Absa Premiership side back in the match.
After a relatively quiet start to the game, Leopards were to draw first blood on 20 minutes when Shivambu struck from close range after the ball had been headed into the box, despite replays clearly showing Shivambu to have been in an offside position in the build up to the goal.
The goal left AmaKhosi looking shell-shocked, the hosts barely getting a sniff at goal for the remainder of the half.
Nothing appeared to be going Chiefs' way, the Soweto giants appearing unfortunate not to have been awarded a penalty on 41 minutes when Mandla Masango looked to have been fouled in the box by goalkeeper Tshinuna Avhashoni.
Things went from bad to worse for Chiefs after coach Stuart Baxter was red-carded for his protests.
AmaKhosi had the first chance of the second half, but Avhashoni was up to the task as he tipped Matthew Rusike’s header over the bar.
With 12 minutes of regulation time to go, Chiefs were finally back in the game when Willard Katsande headed in from Siphiwe Tshabalala’s corner kick.
Chiefs would have been hopeful at taking the game into extra time, if not getting a winner themselves.
But instead it was Leopards who were to break the hearts of the Chiefs fans when a quick attack saw the ball pulled back to Nyundu, whose shot from the edge of the box deflected off a defender and flew into goal with Pieterse caught wrong-footed.