Veteran left-hander Shivnarine Chanderpaul hit 108 and wicketkeeper Denesh Ramdin added 86 as West Indies stretched its lead over Zimbabwe to 206 at close of play on the second day of the second and final test on Thursday.
The hosts, replying to Zimbabwe's modest first-innings total of 175, were 381-8 at stumps at Windsor Park.
The 38-year-old Chanderpaul was typically obstinate as he struck 13 fours, reaching his century off 246 balls before later being caught by Sean Williams off a delivery from offspinner Prosper Utseya.
Earlier, opener Chris Gayle completed his 15th test century before falling for 101, caught by Kyle Jarvis off Utseya, who finished with Zimbabwe's leading bowling figures of 3-60.
Ramdin took 10 runs off the first over after lunch from pacer Jarvis but Zimbabwe's bowlers were disciplined for the most part in the second session without taking a wicket.
Chanderpaul brought up his half century, his 89th score of 50-plus in tests, off 121 balls with his seventh boundary.
An hour later, Ramdin followed him to the milestone, his second straight half century occupying 96 balls.
Jarvis, who struck twice with the new ball on day one, finished with figures of 2-82 while Graeme Cremer also chipped in with a couple of wickets (2-102).