Chasing a mammoth target of 400 runs, the home side were bowled out for just 155 runs.
Shadab Khan was the pick of the Pakistan bowlers as he picked up four wickets and conceded only 28 runs. Faheem Ashraf and Usman Khan bagged couple of wickets each.
For Zimbabwe, Donald Tiripano was the highest run scorer with 44 runs while Elton Chigumbura scored 37 runs.
Hamilton Masakadza and PJ Moor scored 22 and 20 runs respectively.Earlier Pakistan batsmen put up a fine show after skipper Sarfraz Ahmed had won the toss and decided to bat first.
Pakistan openers Fakhar Zaman and Imamul Haq orchestrated a brilliant 304-run opening stand to help the side post a massive total on the board.
The pair broke the world record for highest opening partnership in ODI history while also registering Pakistan’s highest ever partnership for any wicket.
Zaman also became the first Pakistan batsman to score a double century in ODI cricket.
His unbeaten 210-run knock also ensured that he now holds the record for the highest innings played by a Pakistan batsman in ODI cricket.
Imam ably assisted his partner Zamam by scoring his second century of the series. He was dismissed after scoring 113 runs.
Asif Ali — who was promoted higher up the order — provided impetus at the backend of the innings with a breezy half century of just 22 balls, which enabled Pakistan to finish at 399/1 in their allotted 50 overs.
As a reward for his brilliant double ton, Zaman was declared player of the match.
The fifth and final match of the series will be played on Sunday July 22