Bonner was 74 with Joshua Da Silva (22) at the other end in an unbroken 45-run sixth-wicket stand as the Caribbeans reached 223 for five at the Mirpur Sher-e-Bangla National Cricket Stadium on Thursday.
After Kraigg Brathwaite chose to bat, his batsmen dominated the morning session with a 66-run opening stand, scoring 84 for the loss of opener John Campbell (36), taken out by Taijul Islam (2-64), before lunch.
Brathwaite led the fight from the front, smashing 47 before perishing to a stunning catch by Nazmul Hossain Shanto at the slips off Soumya Sarker.
The Tigers’ pacer Abu Jayed (2-46), who was initially wayward, swung the ball in to account for the wickets of Shayne Moseley (7) and Chattogram’s double centurion Kyle Mayers (5) before either could get into the groove and reduced the visitors to 116 for four.
However, Taijul gave a crucial breakthrough when Blackwood popped a return catch to reduce the visitors to 178 for five in the 72nd over.
Even after Bangladesh opted for the new ball, the pair continued playing in the same fashion and maintained temperament to see through the day.
Brief score:
West Indies 1st innings: 223/5 in 90 overs (Brathwaite 47, Campbell 36, Bonner 74 not out, Blackwood 28, Da Silva 22 not out; Abu Jayed 46-2, Taijul 2-64)