The daughter of Invincible Spirit had struggled in two starts this season but back in class 4 company she was able to regain the winning thread.
There were only four runners but three opted to come up the near side rail while one stuck in the middle of the track.
Andrea Atzeni aboard Tantshi was in the group of three and she travelled well throughout in the first-time hood.
He struck the front with over a furlong to run and was soon clear on her side. Maid A Million, in the centre of the track was sticking on gamely, but Tantshi had her measure and went on to score by a neck.
Roger said: "Tantshi was down in grade and this provided a good opportunity for her to get back to winning ways. She could go for a seven furlong fillies' handicap at the July Meeting next."