They won with 262 balls remaining which is the third-largest win in terms of balls remaining in completed women's ODIs.
Van Niekerk finished with 4-0 from 3.2 overs.
It was a ideal call made by South Africa women captain Dane van Niekerk to bowl first after winning the toss, who went on to produce a freakish spell of 3.2-3-0-4.
4/0 Dane van Niekerk's figures - the first instance of a bowler taking four or more wickets without conceding any run across all internationals (men's and women's cricket included).
"If I could script it, I couldn't have scripted it any better", she said.
For West Indies, who registered their second-lowest total in ODI cricket, Chedean Nation was the only batter to reach double digits, scoring 26 off 53 balls with five boundaries.
Van Niekerk nearly single-handedly destroyed the West Indian batting order as South Africa bowled them out for 48.
"They (West Indies) are a very talented team and they are very destructive, we know what they can do".
SOUTH AFRICA - Dane van Niekerk (captain), Trisha Chetty, Moseline Daniels, Nadine de Klerk, Mignon du Preez, Shabnim Ismail, Marizanne Kapp, Ayabonga Khaka, Masabata Klaas, Lizelle Lee, Sune Luus, Raisibe Ntozakhe, Andrie Steyn, Chloe Tryon and Laura Wolvaardt.
On her record-breaking statistic, she commented sheepishly; "The ball was not coming off great, I can't tell you what happened there today". In the opening game against reigning champions Australia Women, they were 123 for two batting first before collapsing to 204 all out.
The team surprised a lot of people by holding a training session directly after the match.
"We don't want to think too much about the end result, that will take care of itself". We spoke about this before we went out to bat that we mustn't get ahead of ourselves, we still have to face some tough competition, including Sri Lanka who are looking good at the moment.