Zimbabwe were teetering on 4-52 at the close of the second day of the second Test after Pakistan declared their first innings on 8-510 with Abid Ali scoring a maiden double century at the Harare Sports Club.
The home team, one down in the two-Test series after losing by an innings and 116 runs last week, are still 458 runs behind with a mammoth task ahead if they are to avoid the follow-on.
Pakistan's 36-year-old debutant bowler Tabish Khan took a wicket in his first over on Saturday and the Zimbabwe top order continued to tumble cheaply as they lost their first four wickets inside the opening 25 overs of their reply.
Regis Chakabva, moved up the order to No.3, provided the only real resistance for the hosts and will resume on Sunday on 28 not out, along with Tendai Chisoro.
Earlier, Abid scored 215 not out as Pakistan picked up where they left off after being 4-268 overnight.
But his knock was overshadowed by No. 9 Nauman Ali, who bludgeoned his way to the brink of a first century but was dramatically stumped three runs short of the milestone.
Nauman was 93 not out at tea and smashed four runs off the first ball of the evening session before swinging at a wide one and losing his balance momentarily to allow Zimbabwe wicketkeeper Chakabva to whip off the bails.
Pakistan declared immediately to put Zimbabwe into bat for almost all of the last session and the bowlers turned the screw for the touring side.
Australian Associated Press
