Zaheer, who has played just seven Tests after the 2011 World Cup, conceded 11 runs in six overs he bowled in the first session.
Zaheer, who has failed to take five wickets in a Test innings since October 2010, is seeking to return to the national side ahead of the West Indies tour to India in November.
The 34-year-old, who has taken 295 international wickets from 88 Tests and 282 wickets from 200 ODIs, has been left out of the India squad since last year after he picked just one wicket against England at the Eden Gardens.
They understand a big total will open doors for clinching the three-match series.
The opening pair of Kraigg Brathwaite and Kieran Powell (33) began their innings with caution but just before lunch the latter gave a catch to Mohammad Kaif in the deep off left-arm orthodox spinner Bharghav Bhatt.
Captain Kirk Edwards and Brathwaite are batting at eight and 25 respectively.