Dubai: West Indies were 69-1 at close in reply to Pakistan's big first innings total of 579-3 declared on the second day of the first day-night Test in Dubai on Friday.
Kraig Brathwaite was unbeaten on 32 and Darren Bravo on 14 not out at close as West Indies need to reach 380 to avoid follow-on.
Azhar Ali hit a maiden triply hundred with 302 not out to anchor Pakistan's innings which also had contributions from Sami Aslam's (90), Babar Azam (69) and Asad Shafiq (67).
This is the second ever day-night Test after Australia and New Zealand played the first at Adelaide in November last year.
His was the fourth triple hundred by a Pakistani batsman.
Apart from him and Inzamam, late Hanif Mohammad knocked 337 against West Indies at Bridgetown in 1958 and Younis Khan made 313 against Sri Lanka in Karachi in 2009.
Since his arrival on the international scene, Ali has impressed with his resolute batting and is likely to anchor Pakistan's batting once Younis and skipper Misbah-ul-Haq leave the stage.
He has already replaced Misbah as captain of the one-day team.
Ali dedicated his triple hundred to his parents and also to the people of his nation.
Manufacturers of the pink ball modified its seam from green and white after players had complained sighting problems in the first-ever day-night Test between Australia and New Zealand in Adelaide last year.
Brief scores
Pakistan - 579 for 3 dec (Azhar 302*, Aslam 90, Bishoo 2-125)
West Indies - 69 for 1 (Brathwaite 32*)
Status - West Indies trail by 510 runs