Despite a fighting half-century from Jermaine Blackman, England are in complete control at tea on the second day of the third and final Test at Kensington Oval.
Blackwood’s unbeaten knock of 67 has been the only resistance encountered by the English bowlers, who have the Windies reeling on 139 for seven.
West Indies resumed their innings after lunch on 37 for three and quickly lost four wickets.
Darren Bravo was the first to go when he was caught by Christopher Jordan off the bowling of off-spinner Moeen Ali for nine.
Blackwood came in to join veteran left-hander Shivnarine Chanderpaul, but Chanderpaul scored 25 before he was removed by a stunning slip catch taken by Jordan with the score on 82 for five in the 28th over.
Captain Denesh Ramdin made just 13 runs, and Jason Holder was dismissed for nine to leave the home side in further trouble.
Versammy Permaul was not out on one along with Blackwood. (ML)