Francis Nambute and Shaban Kenga were the scorers in the tie as Bandari honoured their postponed match after the Caf Confederation Cup.
A nice combination of play between William Wadri and Abdalla Hassan in the 10th minute almost resulted in an opening goal for the Dockers, but Hassan lost his footing.
Posta Rangers struck the first goal of the match in the 21st minute after Bandari goalkeeper Michael Wanyika spilt the ball in front of him. The Posta Rangers forward, with considerable calm, tapped the ball home to stun the hosts who had been dominant all through.
Bernard Mwalala's side almost equalized in the 28th minute after Posta Rangers backline did not clear their area quickly amid bombardments from the coastal-based side. Kenga had instigated another clever move forward and found Darius Msagha whose final shot deflected off Michael Apudo and the ball flew slightly over the bar.
Bandari won a free kick in a very promising position in the 38th minute which Wadri delivered but goalkeeper Jairus Adira managed to punch the ball back into play in a crowded box.
Kenga restored parity in the first minute of added time before the first half ended. Running across the right-wing, Abdalla managed to pick Kenga with a sumptuous cross and the scorer just had to rise slightly above the rest to head home. It was a deserved equalizer for Bandari.
Wanyika denied Nambute once more in the 55th minute after Posta Rangers won a corner which the forward met to head but the former Kakamega Homeboyz goalkeeper was keen to parry it away.
Mwalala's changes in the last 10 minutes where he brought on Mohammed Siraj and Cliff Kasuti in place of Hassan and Msagha respectively did not bear any fruit as the tie ended in a 1-1 draw.
Posta Rangers will host winless Kisumu All-Stars on October 5 at Kenyatta Stadium while Bandari will be up against Sofapaka the next day but on the same ground.