Twitch put a below-par effort at York behind her to take the Listed honours in the British Stallion Studs EBF Beckford Fillies' Stakes at Bath.
The four-year-old had been in the frame at both Listed and Group Three level before not sparkling behind Abingdon in the Galtres Stakes at York.
However, the Hugo Palmer-trained filly showed her true colours with a gutsy display over a mile and a three-quarters.
James Doyle brought her to challenge on the stands' side as the field fanned out all across the track in the straight.
Twitch (12-1) got on top in the final 100 yards to score by half a length from Vive Ma Fille.
Anzhelika was another three-quarters of a length away in third.
Doyle told At The Races: "Hugo was very pleased with her coming into this race.
"The race went to plan. We got a nice toe into the race. She quickened up and saw it out really well.
"The ground's getting a little bit poached and it's on the easy side.
"She was inclined to go towards the stands' side.
"It was fresh ground, she got her momentum going and I didn't want to hinder her."