It was Sri Lanka's lowest total in the five-match series which it trails 3-0. Sri Lanka was dismissed in 43.4 overs.
Fast bowler Hasan Ali celebrated his elevation to No. 1 in the ODI rankings with 3-37.
Lahiru Thirimanne (62) scored a fighting half-century but the rest of the top order continued their poor form after captain Upul Tharanga won the toss and elected to bat first.
Tharanga was among three batsmen to be dismissed for ducks. He was clean-bowled by pacer Usman Shinwari off the second delivery of his debut.
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Sadeera Samarawickrama, one of three changes Sri Lanka made in the playing XI, had a forgetful ODI debut when left- arm spinner Imad Wasim (2-13) clean bowled him for 0.
Legspinner Shadab Khan (2-29) removed Seekkuge Prasanna and Thisara Perera off his first two deliveries to make it 99 -7.
Thirimanne's resistance finally ended when he played a loose drive in Wasim's return spell, and Ali wrapped up the innings.