After dismissing Jonathan Trott, captain Alastair Cook and Gary Ballance in quick succession, the West Indies let their advantage slip by allowing Ian Bell and Joe Root to stabilise the innings with a 177-run partnership.
Things went from bad to worse for the hosts, with Bell going on to score his 22nd Test century during his 130-run stand with Ben Stokes, who finished unbeaten on 71, after Root was dismissed for 83.
"The guys bowled a full length. The ball swung early," Roach, who took two wickets, said after the first day. "I think 'Bobby' [Taylor] bowled exceptionally well, Jason bowled exceptionally well, and myself as well.
"We wanted more wickets in the first session but three wickets was fantastic going in at lunch but after lunch, that's probably where we went wrong. We weren't consistent enough."
However, Roach was glad to have dismissed Bell for 143 in the penultimate over of the day.
"A little bit of an effort ball – obviously the last ball of a spell, so I wanted to finish strong," he said. "I think the pitch helped me as well, the ball just kicked there and shaped away and hit his edge, so I'm thankful, obviously, that's him out. But obviously I've got to work on the rest of the batsmen tomorrow."