Abdullah Shafique led the charge with an unbeaten 107, bringing up his sixth Test hundred and first since 2024. The opener reached three figures with the final delivery of the day, driving Jomel Warrican through midwicket.
He had earlier raised his half-century with successive drives off Kemar Roach and looked comfortable against Warrican's spin, using both the sweep and lofted shots over extra cover to good effect.
Babar Azam finished undefeated on 86 after a polished innings that left him only 14 runs short of ending a four-year wait for a Test century. He attacked Jayden Seales early with three boundaries, remained positive throughout and expertly managed the closing stages by rotating the strike to preserve Pakistan's advantage.
Together, he and Shafique shared an unbroken 168-run stand for the third wicket, steering the hosts clear of the batting collapses that had plagued their recent Tests.
Pakistan had set the tone from the outset despite Shan Masood's absence. Azan Awais struck the second ball of the innings for four and hammered Roach for three consecutive boundaries, forcing the veteran out of the attack.
Awais added a brisk half-century before falling lbw to Warrican after a successful review confirmed the ball would hit leg stump.
Earlier, West Indies added 105 runs to their overnight total as Justin Greaves (73) and Roston Chase (70) completed half-centuries.
Ubaid Shah removed Chase with his first ball of the day, Ali Usman dismissed Greaves with his opening delivery, and Sajid Khan claimed 4 for 85 as the tourists were eventually bowled out for 344.
Kemar Roach offered stubborn lower-order resistance, while Shamar Joseph's aggressive cameo ended when Sajid bowled him after the fast bowler had earlier clocked the quickest deliveries of the series at just under 150 kph.
Joe Root will return to the captaincy when England begin their three-match Test series against Pakistan later this month, with selectors announcing a 16-man squad for the opening two fixtures.
West Indies Test captain Roston Chase admitted it was a combination of team balance, a spin-friendly pitch and tactics that led to their eight-wicket loss to Pakistan.
Pakistan wrapped up an eight-wicket victory on the fourth day of the second Test against West Indies in Trinidad, to see the tourists walking away with a 1-1 draw in the two-match series.
In a near-perfect day of Test cricket that ebbed and flowed, Pakistan found themselves on top at the end of play on day three in Port of Spain in the West Indies.
