**Josh Thomas' late charge-down try guided Ospreys to a sensational 24-19 comeback win over Guinness PRO14 giants Leinster at the RDS.** With replacement Andrew Smith sin-binned, Leinster lost their grip on a 19-3 lead as Ospreys ruthlessly reeled off converted scores from Olly Cracknell (68 minutes), Owen Watkin (71) and Thomas (75). It was a season-defining result for Toby Booth's men as it guarantees them a third-placed finish in Conference A and Heineken Champions Cup rugby for next season. The defeat will certainly sharpen Leinster minds ahead of next week's PRO14 final against Munster.