Daine Klate scored the only goal of the match in the first half, but Amakhosi had a number of chances late on to at least salvage a draw going into the return leg on September 24.
Pirates’ last competitive game was the 4-1 thumping of Egyptian giants Zamalek, and the confidence was clearly still with them as they completely dominated the early exchanges.
Chiefs, by contrast, were playing their first match in 14 days, and it showed as they were all over the place for the first 40 minutes.
Even the usually brilliant Itumeleng Khune showed signs of nerves as he flapped at an early Tlou Segolela cross which was eventually cleared to safety.
Shortly afterwards Tsepo Masilela showed all his experience with a timely block from Lennox Bacela’s shot, but there was nothing anyone could do for the opener on 12 minutes.
Mulomowandau Mathoho had given away a cheap foul on the edge of the area, and Klate stepped up to bend a pin-point curling free-kick just inside the left-hand upright.
Chiefs were nowhere at this point, losing the ball all too regularly and allowing Pirates to attack down the flanks. Even the in-form Siphiwe Tshabalala spent more time tracking back to defend rather than getting his team on the front foot.
In fact, it took 36 minutes for the home side to get their first shot on target, and even then it was a weak headed attempt by Mathoho.
But slowly but surely Chiefs found their way back into the game, and Siboniso Gaxa came close on two occasions just before the half-time whistle … a sign of things to come.
Stuart Baxter brought Knowledge Musona on at the start of the second half and the Zimbabwean made an instant impact as he twice fired shots at target.
Chiefs came even closer on 68 minutes when Bernard Parker showed some great skill to lob the ball over Lucky Lekgwathi before firing in a shot which beat Senzo Meyiwa, but the effort came back off the up-right.
‘Shabba’ was also getting forward a lot more and three minutes later he powered in a shot which came back off Meyiwa’s chest, while his follow-up effort was blocked.
It took Pirates a while to get back into the second half, but they did have two decent chances towards the end.
First substitute Kermit Erasmus had his header deflected wide, before debutant Thamsanqa Gabuza headed over when perhaps he should have done better.
Still Chiefs had late chances to get level, but Tshabalala, Musona and Kingston Nkhatha flashed shots just wide of the right-hand up-right, while Musona also hit his effort straight at Meyiwa after fashioning some space for himself in time added on.