Fast bowler Usman Shinwari dominated Sri Lanka's top order with 5-34 as Pakistan whitewashed the tourists 5-0 for another convincing nine-wicket victory in the fifth and final one-day international on Monday.
Shinwari claimed all his wickets in a 21-ball spell to dismiss Sri Lanka for 103 in only 26.2 overs.
Fakhar Zaman (48) and Imam-ul-Haq (45 no) then eased to 105-1 in 20.2 overs to cap Pakistan's string run in the ODIs in 2017 that began in June when it won the Champions Trophy.
Sri Lanka's poor run in limited-overs continued this year under captain Upul Tharanga. South Africa and India had earlier routed Sri Lanka 5-0 and the country has now lost 12 ODIs in a row.
Shinwari, playing in only his second ODI, claimed four of his wickets in his first two overs before adding one more to make Sri Lanka 20-5.
The last wicket pair of Dushmantha Chameera (11) and Vishwa Fernando (7) took Sri Lanka beyond the 100-run mark before No.1-ranked fast bowler Hasan Ali finished off with 2-19 by clean bowling Chameera.
Shinwari was on a hat trick in the first over when he had Sadeera Samarawickrama clean bowled for his second straight nought of the series and then lured Dinesh Chandimal to drive but only got a big outside edge.
Tharanga, who won the toss and opted to bat first, drove the hat-trick ball to cover boundary before Shinwari had the skipper bowled off a delivery that nipped back sharply into the left-hander.
Niroshan Dickwella was the third man to get dismissed for nought when Shinwari had him lbw off another sharp incoming delivery. Milinda Siriwardana capped Sri Lanka's top order batting woes in the series when he played another lose drive to get caught at covers.
Ali then reduced Sri Lanka to 49-6 when Lahiru Thirimanne (19) was caught behind and Seekkuge Prasanna was run out.
Thisara Perera (25) was one of the four batsmen to cross the double-figure mark, hitting a six and three fours, before falling to legspinner Shadab Khan, who finished with 2-24.
Imam and Zaman then hurried the run-chase with an opening stand of 84 runs off 100 balls before Jeffery Vandersay got the consolation wicket by having Zaman caught behind. Zaman hit seven fours.
Imam raised the victory by cutting Vandersay to the boundary as Pakistan made a remarkable turnaround of form with a 5-0 victory after losing the test series 2-0.
The teams will now play a three-match Twenty20 series, starting from Thursday with the final T20 scheduled to be played at Lahore on Sunday.