However, 23 wickets at 16.17 in the Regional 4-Day Tournament has convinced the selectors Roach deserves another chance in three Tests, including the first day/night red-ball worldwide, in England.
Marsh, so pivotal with the bat, dismissed the unsafe Stafanie Taylor lbw for a 12-ball duck but with DRS available had the West Indian captain reviewed she would have been reprieved with the ball sliding down the leg side.
Wicketkeeper Sarah Taylor was dismissed for nought, the second wicket to fall after sending a thick edge off Deandra Dottin to Hayley Matthews with only 54 on the scoreboard.
Leg-spinner Afy Fletcher sends down a delivery during her impressive 10-over spell against England Women on Saturday. Both sides surpassed the 300-mark on that occasion, making 678 runs in total, the highest cumulative score in women's one-day worldwide history.
'With that first defeat against India we made it hard for ourselves but since then we've been outstanding.' England captain Heather Knight said.
But Matthews was hit in front to Hartley and lbw in the 24 over and Deandra Dottin (7) missed a sweep at off-spinner Heather Knight and was also lbw 20 balls later at 73 for four in the 27th over.
In reply, West Indies soon found themselves two wickets down in the 13th over with less than 40 on the board after opener Kycia Knight was run out for 17 and Taylor trapped leg-before by Marsh.
Matthews (29) opted to review her lbw dismissal, against Alex Hartley, but to no avail, with her departure triggering a collapse of 6-36 - Sciver taking two wickets in her first over, thanks in part to an excellent running catch at deep backward square by Beaumont to dismiss Chedean Nation (23).
Akeira Peters fell lbw to Brunt for a duck with West Indies then 100 for eight in the 37th over as the run-rate edged into double figures.
India will meet now meet holders Australia in the other semi-final at Derby on July 20.
"We wanted to put in a really professional performance and there was that carrot of finishing top of the group to stay here in Bristol", Knight told Sky Sports.
Beaumont said: "We fielded and bowled well and won by 92 runs in the end so it's good for us".
"We can now stay in Bristol and plan for the next few days ahead of the semi-final".