Pakistan lost four wickets for 83 in the last session, including that of Yousuf who made 102, his 22nd career hundred.
Yousuf broke the old record of seven hundreds in a calendar year jointly held by West Indian Vivian Richards and Sri Lankan, Aravinda de Silva.
Yousuf's hard fought century was also his sixth against the West Indies in eight Tests and his fifth in successive matches. He has now accmulated 1,664 runs in 11 Tests this year.
Apart from his stylish knock the rest of the batting was unimpressive.
West Indian bowlers Jerome Taylor, Corey Collymore, Daren Powell and Dwayne Bravo all bowled manfully on a pitch which is already keeping low and is slow in pace.