Tinashe Panyangara took two for 15 as Pakistan were reduced to 27 for three in the first hour in Harare but they reached lunch on 74 with no further damage.
Sikandar Raza made his Zimbabwe debut in place of Sean Williams, the one player who refused to play due to a dispute with Zimbabwe Cricket over salary payments.
Hamilton Masakadza, deputising as Zimbabwe captain with Brendan Taylor absent following the birth of son Mason on Monday night, won the toss and asked Pakistan to bat first.
Khurram Manzoor struck a couple of early boundaries but the home side were soon celebrating in the seventh over when Tendai Chatara angled a ball in to Mohammad Hafeez, who edged to Vusi Sibanda at second slip to depart for five.
Chatara welcomed Azhar Ali with a nasty lifter and runs were hard to come by in the next few overs, though a misfield gifted two runs to Manzoor.
The latter was sent on his way by Panyangara, though, when, having made 11, he was pinned in front by a sharp off-cutter and despite concerns over height, umpire Ranmore Martinesz ruled the ball would have hit the stumps.
Azhar survived a run-out chance but Younus Khan departed for three when he was surprised by extra bounce from Panyangara and played on.
The stage was set for a trademark Misbah resistance but two early half-volleys allowed the Pakistan captain, often criticised for his slow scoring in limited-overs internationals, to hit his stride with boundaries either side of the wicket.
Azhar's first boundary came off his 52nd delivery and the pair added an unbroken 47 by lunch, with Azhar 24 not out having been overtaken by his skipper (31no).
Zimbabwe opening batsman Tino Mawoyo, recalled after a long lay-off caused by a groin injury, was forced off shortly before the interval having injured his thumb cutting off a drive from Azhar.