The visitors began the day in the commanding position of 266/2 in pursuit of 344, but the West Indies fought back to restrict them to just a 43-run lead. However, they floundered with the bat and were just 60 runs ahead with six wickets down at the close of play.
Pakistan captain Barbar Azam (88) added just two to his overnight total before pressure resulted in a hurried single, Brandon King got the direct hit and Azam didn't make his ground.
And the wickets continued to tumble as they lost three more before lunch. Chief destroyer Jomel Warrican clean bowled Awais Zafar and Mohammad Rizwan, while Shamar Joseph trapped Salman Agha in front for a duck
Centurion Abdullah Shafique (160 not out) continued to prod and probe in the chaos around him and finally found a willing partner in Sajid Khan (30). The pair went past the West Indies total and put on a gritty 59 runs together before Jayden Seals got the breakthrough, leaving them 370/7.
Seamer Warrican returned to wrap up the tail in quick time and ended with deserved figures of 6/112.
The West Indies started their second innings well enough, but Tagenarine Chanderpaul (17) fell to spinner Khan with 40 on the board. On a deteriorating pitch, Khan went to work to pick up three more scalps before the close of play, leaving the hosts 103/6, only 60 runs ahead.
Pakistan seized control of the second Test by stumps on day two, reaching 266 for 2 in reply to West Indies' 344 to trail by just 78 runs after producing their strongest batting display of the series.
West Indies reached 239-5 at stumps on the opening day of the second Test against Pakistan at Queen's Park Oval in Port of Spain after winning the toss and electing to bat.
India are expected to be without pace spearhead Jasprit Bumrah for their upcoming two-Test series against Sri Lanka after the BCCI medical team advised against rushing his return from a persistent left knee injury.
West Indies fast bowler Alzarri Joseph has hit back at head coach Daren Sammy that suggested that the paceman "declined selection" for the ongoing Test series against Pakistan.
