West Indian quick Roach conjured a sensational spell of fast bowling on day two of the first Test, taking five for 17 as the tourists were rolled over for 77.
Play will resume on Friday with England 339 behind, on course for a three-day defeat despite a fightback with the ball leaving the hosts 127-6.
England’s score was the lowest-ever Test innings at the famous Kensington Oval, instantly calling to mind the previous Caribbean calamities in Trinidad, where they made 46 in 1994, and Jamaica when they were skittled for 51 a decade ago.
The current crop are no strangers to collapsing either, most recently rolled over for 58 in Auckland last March.
Roach deserved endless credit for his inspired performance on home soil, while Jason Holder, Alzarri Joseph and Shannon Gabriel offered faultless support, combining to create a crushing feeling of inevitability that unsettled the tourists.
Moeen, who top-edged Roach to fine-leg for a golden duck, said: “It’s difficult to stop guys who are bowling well with their tail up.
“Sometimes in the changing room you know what is going to happen...that they have the momentum.
“You try and go in and stop that, either by taking the momentum away from them or by grinding it out, but there are times when you will just get bowled out for not many. Every team does.
“I feel over the last few years it’s happened often where we’ve lost wickets at the top but previously we’ve been able to get a score.”
Captain Joe Root was lauded for his attacking approach during the 3-0 whitewash of Sri Lanka before Christmas and Moeen confirmed the same instructions are still in place.
“Rooty’s message was to still go out there and try to score, try to be positive. Today it just didn’t happen,” Moeen said.
Roach cut a contented figure after turning in one of the finest performances of his career and was supportive of the decision not to enforce the follow-on.
Holder must have been tempted to send a punch drunk batting side back in for round two but instead allowed his pacemen to take a breather.
“It’s a special feeling and I’m very proud of my achievement,” said Roach.
“Today was my day but kudos to all our bowlers, we went out there and hit the nail on the head. A lead of 400 is the target, on that pitch it would be pretty tough for them.
“I wouldn’t have wanted to bat last on that pitch so it was best for us to have another hit out before we got at the English again.”
England’s team selection for the match is under the microscope, with Stuart Broad’s absence looking increasingly awkward on a pitch that would have suited his style.
“I would have played two spinners when I saw that pitch,” Moeen said. “Looking back, the West Indies played one spinner and he hasn’t even bowled yet, but as a team you can’t look and say ‘we should have picked this guy or that guy’.”
Broad was spared the grim viewing of England’s batting, with he and Chris Woakes not present at the stadium after being given a day off.