The visitors resumed day four on 168 for four with Younis needing another 25 runs to make his 22nd Test century, and the 35-year-old made it to three-figures unscathed to guide Pakistan on to 257 for five at lunch.
Zimbabwe continued their trend of starting a session with the upper hand as Tendai Chatara struck in the opening over of the day to remove Asad Shafiq.
Shafiq failed to add to his overnight total of 15 before being bowled by a superb delivery from Chatara, with the seamer claiming his second wicket of the innings.
But that proved to be the only breakthrough of the morning as Younis (115 not out) was joined at the crease by wicket-keeper Adnan Akmal, who helped himself to seven boundaries as he reached lunch unbeaten on 46.
The partnership of 89 left Pakistan with a lead of 180 with five second-innings wickets in hand as they looked to build an insurmountable total in the opening Test of the two-match series.
- Sports & Recreation
- Tendai Chatara