La Dosia has given champion racehorse So You Think his first Group One win as a sire with her victory in the New Zealand Thousand Guineas at Riccarton.

Trained by Mandy and Matt Brown, the filly was ridden by Racha Cuneen who has been aboard for her four starts this spring which include two Listed wins before Saturday's feature.

Out of Group Two-winning mare Star Affair, La Dosia has now won four of her six starts from 1000m to 1600m and claimed the Thousand Guineas by 1-1/2 lengths from Bella Gioia.

So You Think was trained in Australia by Bart Cummings to win five Group One races including two Cox Plates.

After Coolmore bought a major share, the horse was transferred to Aidan O'Brien and won another five Group One races in Ireland and England.

He now shuttles between Ireland and Australia where he stands at Coolmore for $49.500.