Goals from Mpho Makola, Oupa Manyisa and Thembinkosi Lorch, along with a Joseph Okumu own-goal, overshadowed Sifiso Mbhele's goal for Ea Lla Koto.
Stars looked to pick up where they left off in their 3-2 league victory at the same venue a week ago as they threatened Siyabonga Mpontshane's goal early on.
Ayanda Dlamini had the first real opportunity as he created space for himself on the edge of the area before his curling effort had Mpontshane palming the ball out for a corner.
The resultant set-piece then had the Bucs keeper diving low to keep out a Mbhele shot from close range after a goal-mouth scramble.
The visitors then opened the scoring through Mpho Makola, who got the beating of Christoffer Mafoumbi with a swerving shot from distance in the 20th minute.
Mpontshane was eventually beaten as Mbhele headed home a great ball in from Bokang Tlhone, after poor defending from the Bucs on the 40-minute mark.
Makola could have added a second to his name just before the half-time whistle as he forced Mafoumbi into a excellent save with a low, curling effort from close range.
Pirates went ahead once again just three minutes into the second half as centre-back Okumu turned Makola's cross into his own net, as Mafoumbi coud only look on as the ball krept in at the far-post.
Manyisa added a third just after the hour-mark as he stole possession on the half-way line before great inter-passing involving Tendai Ndoro saw the skipper rush through on goal and lob an on-rushing Mafoumbi with great composure.
Lorch then sealed the result with a well-taken volley from Makola's free-kick deep into stoppage time to humiliate the home side in an act of revenge.