After the loss of three wickets in the morning session, West Indies steadied their innings in the second session without conceding any wickets as Powell collected 115, while Chanderpaul added 46.
The flamboyant Chris Gayle became the first player to hit a six off the first ball of a Test match, when he launched his big-hit against the hosts.
Gayle smashed debutant Sohag Gazi over long-on, taking 18 from the first over but the 21-year-old off-spinner took revenge by having the opener caught for 24.
In the second over after tea, Powell was dismissed on 117 by Gazi, who claimed Gayle and Darren Bravo.
But Chanderpaul continued on to his 26th century, reaching 123 not out off 195 balls at stumps. Denesh Ramdin was also unbeaten on 52 off 88 balls.
Gazi removed opener Gayle for 24 and Bravo for 14 to go into lunch on two for 32 from his first 11 Test overs after West Indies skipper Darren Sammy won the toss.
Gayle was out when he attempted to send the ball over the long-off fielder, instead providing an easy catch for Mahmudullah.
Bravo was caught by Rubel Hossain at point after he went for a big drive.