Sri Lanka were given a scare when they were reduced to 44-3 in the 11th over after losing captain Kumar Sangakkara and Sanath Jayasuriya in the space of three deliveries.
Mahela Jayawardene's dismissal in the 23rd over made it 74-4, but the fifth-wicket pair of Kapugedara and Thilan Samaraweera (38 not out) put on 95 runs to hand the hosts a 2-0 lead in the five-match series.
The tourists paid for a shoddy batting display after being sent in to bat in overcast conditions and were bundled out in 47 overs.
buy zydena online buy zydena online no prescription
The 26 extras sent down by the Sri Lankan bowlers, including 18 wides, were the highest contributor in Pakistan's innings.
The tourists were reduced to 128-9 before the last pair of Mohammad Aamer (24) and Saeed Ajmal (16) gave the top order a batting lesson by adding 40 runs.