Eoin Morgan's men appeared set for defeat several times towards the end of their run chase at Warner Park, where all-rounder Chris Woakes came to the rescue with an unbeaten 47 from number seven to chalk up a second successive warm-up victory over the past three days at this same venue.
England can therefore journey on to Antigua on Tuesday with confidence intact for the first of three one-day internationals against West Indies at the end of this week.
They had Woakes to thank, and assistant coach Paul Farbrace – in sole charge for this brief tour, in the absence of Trevor Bayliss - admitted they ought to have won more easily.
Jonny Bairstow got them off to a fine start.
Pressed into service as an opener with Jason Roy sitting the match out as a precaution because of his bruised right palm, he responded with a commanding innings of 86 in pursuit of 233 all out.
"On that pitch, making no excuses, it got tougher – and the ball stopped," said Farbrace.
"But even so we made it a lot harder for ourselves than we needed to ... one bloke gets 130 not out, and you win the game comfortably."
England very definitely did not do that - and had only seven balls to spare - having found themselves with an awkward chase after their unheralded hosts recovered from 55 for five thanks to a counter-attacking century stand between Jahmar Hamilton (73) and the giant figure of 6ft 7in, 22 stone Rakheem Cornwall (59).
The reply was on course while Bairstow and Joe Root were together in a second-wicket partnership of 117.
But they then lost six wickets for 49 runs, leaving the salvage job to Woakes, whose run-a-ball innings shepherded crucial stands with Adil Rashid and then Liam Plunkett.
"It was the sort of pitch that got tougher and tougher," added Farbrace.
"We talked the other day about how cricket out here tends to be four quarters – first 25 overs is a lot easier to bat than the last 25 overs."
England have a variety of injury concerns, including Jake Ball who limped out of the attack with knee trouble after bowling just 2.1 overs, and opener Alex Hales, due to fly to Antigua on Tuesday to continue his rehabilitation from a broken hand rather than as yet added to the squad.
They are at least confident Roy will be fit to face West Indies on Friday, though.
"He could have easily played and easily fielded the other day [in Saturday's first warm-up fixture]," said Farbrace.
"But he has a 'hotspot', which has bled through to the back of the hand and caused a swelling – so there's no point making it worse.
"He got runs in that first game, so there was no point causing any more damage really."
