KINGSTOWN, St Vincent – Off-spinner Onaje Amory’s brilliant four-wicket haul proved futile as West Indies Under-19s slumped to a narrow one-wicket loss in a low-scoring affair here Thursday.Defending an inadequate 107 in the third Youth One-Day International at Cumberland Playing Field, West Indies made a fist of it, largely courtesy of Amory’s four for eight off four overs, but came up short as South Africa Under-19s got home in the 19th over.Opener Ethan Cunningham top-scored with a breezy 25 off 23 balls but it was number nine Liam Alder, who struck a 12-ball unbeaten 24, which made the difference in the run chase towards the end.