Ganga steered West Indies to 191 for six at close on day two with his defiant and unbeaten knock on a slow, low bouncing pitch on which Umar Gul and Danish Kaneria took six wickets.
Ganga, who has faced 214 balls and batted for 308 minutes, ensured his team were not rolled over by the home side, who were bowled out for 304 one hour into the morning session.
Scorecard of Test 3 Day 2
After a solid 51-run opening stand between Ganga and Chris Gayle, who stroked his way to 40 from 54 balls, West Indies were rocked by pacer Gul who took three wickets in 10 balls.
He had Gayle caught at mid-on by Abdul Razzaq and two balls later bowled skipper Brian Lara with a beauty that moved away and took off-stump in his first over after lunch.
Lara failed to get off the mark after scores of 61, 122 and 216 in the previous two Tests.
Next over, Gul produced an unplayable, in-dipping yorker to clean up Ramnaresh Sarwan, back in the side after being dropped for the second Test, also for a duck.
Ganga revived the visitors from a precarious 51 for three with a 63-run stand with Shivnarine Chanderpaul for the fourth wicket, the latter picking the gaps beautifully to score 36 from 49 balls with seven fours.
Chanderpaul fell just before tea, caught at forward short leg by Imran Farhat off leg-spinner Danish Kaneria.
Kaneria also grabbed the fifth wicket when he ended an obdurate knock of 21 by Runako Morton, who was given out caught at silly point although television replays suggested the ball might have come off fielder Farhat's helmet.
Kaneria took his third wicket just before stumps when he lured Dwayne Bravo (8) into going for a cut and edging to keeper Kamran Akmal.
Earlier, Corey Collymore finished with three for 57 as Pakistan lost their last three wickets for 47 runs, the last-wicket pair of Gul (26) and Kaneria (7) putting on 32 valuable runs.