Pale Mimosa kept Estimate at bay to claim the Weatherbys Hamilton Insurance Lonsdale Cup at York.
Having just her third start of the season, the Dermot Weld-trained mare travelled powerfully up the long Knavesmire straight in the hands of Pat Smullen after Forgotten Voice had taken the field along.
Hitting the front just over a furlong out, the 2-1 favourite stayed on strongly to hold the late thrust of Ryan Moore on the Queen's Estimate, who stuck on well but could never quite get to the winner, going down by half a length.
Smullen said: "She's a very good mare when everything is right for her, she's just a bit fragile and the boss has done a great job of minding her and keeping her right.
"I was glad we had a drop of rain last night as it just took the real firmness out of the ground, that was our concern but when conditions are right she is good.
"She travelled beautifully and at halfway I was very confident, they just give you that feel when everything is going right.
"She's not just a dour stayer, she has a turn of foot as well.
"She doesn't need it very soft, just a bit of kindness in it.
"Hopefully we'll have a good autumn with her."
Weld said: "I was delighted with her, she's a very progressive mare. "She won well at Leopardstown and was here two years ago in the Galtres. They were two very brave fillies fighting it out, her heart was in the right place under a tactical ride.
"The race was run to suit her and Pat had her in the right position throughout.
"The plan was to sit handy and not many others ride a better type of race than Pat. We had no worries about the ground today and it looked a very good renewal."
Asked about a Melbourne Cup bid, Weld said: "We'll see. The problem is she loves a bit of ease in the ground, and the track here was beautiful.
"We'll think about it, and certainly discuss it in great detail. She's a wonderful staying mare to own."