Opener Fakhar Zaman led the charge with a brilliant 127 off 99 balls, hitting 11 fours and six sixes. Saad Baig contributed 74 from 75 deliveries, including 11 boundaries, while Arafat Minhas produced a blistering 61 off just 31 balls, striking four sixes and three fours.
Pakistan reached the target in 48.3 overs, losing six wickets, according to the match figures reported in the headline and opening account.
Earlier, Sri Lanka posted 325 runs after being sent in to bat. Kamindu Mendis top-scored with 131 off 128 balls, including 12 fours and two sixes. Pavan Rathnayake added 77 from 65 deliveries, while Avishka Fernando scored 38.
Dasun Shanaka made 17, Sahan 15, and the remaining lower-order batters contributed smaller totals.
Pakistan’s pace attack shared the wickets, with Shaheen Shah Afridi, Naseem Shah, Salman Ali Agha and Haris Rauf each claiming two wickets.
Pakistan won the toss and elected to field first. Sri Lanka captain Kusal Mendis said his side would play with confidence, while Pakistan captain Shaheen Afridi expressed determination to deliver a strong performance in the decisive match..