Daine Klate got a brace, and Benni McCarthy and Mpho Makola scored a goal each. Ayanda Gcaba had a goal disallowed in the second half.
Pirates should have buried Swallows with an avalanche of goals but were at times too casual in front of goal, especially after realising they had no strong opposition in the Swazi side.
The game went into break with Pirates leading 3-0, after goals from Klate and McCarthy.
The Swazi side scored their consolation goal through Sabelo Ndzinisa in the second half, before Mpho Makola made it 4-1.
Bucs line-up: Josephs (Mhlongo) – Lekgwathi, Sangweni, Mahamutsa, Gcaba – Myeni, Manyisa (Ntshumayelo) (Makola), Jali (Moholo), Klate (Mayambela) –McCarthy (Mbuyane), Mabena