Sri Lanka was bundled out for 211 in 45.2 overs by Pakistan in the third and final One-Day International of the three-match series in Rawalpindi.
Sadeera Samarawickrama top scored with 48 off 65 deliveries while stand-in captain Kusal Mendis hit 34 in 54 balls.
Debutant Pavan Rathnayake was the last man to be dismissed after scoring 32 off 37 balls.
Although several players got starts no batter was able to guide Sri Lanka towards a competitive total.
For Pakistan, Mohammad Wasim picked up 3/47 while Haris Rauf and Faisal Akram claimed two wickets apiece.
Earlier, Pakistan won the toss and sent Sri Lanka to bat first.
Both teams made four changes to their respective playing XIs from the previous encounter.
Sri Lanka trails the three-match ODI series 0-2.
