Australian mare Ortensia followed in the hoofprints of her illustrious compatriot Black Caviar when speeding to victory in a British Group One sprint, with a remarkable success in the Coolmore Nunthorpe Stakes at York.

Ortensia has taken some time to deliver though, disappointing on her British bow in the King's Stand Stakes at Royal Ascot where Black Caviar maintained her unbeaten record in the Diamond Jubilee Stakes.

It took a couple of races for Ortensia to find her stride, but after struggling on heavy going in the July Cup at Newmarket, she came good in the King George Stakes at Glorious Goodwood.

The icing on the cake came on the Knavesmire, where she came from a long way behind to snatch a Group One under the nose of Spirit Quartz, who she had also beaten into second place at Goodwood.

Paul Messara's seven-year-old was almost last and at least 10 lengths behind at halfway.

However, William Buick kept his cool as he pushed her up the far side of the track and the well-backed 7-2 joint-favourite collared Spirit Quartz in the shadow of the post to collect by a neck.

Course specialist Hamish McGonagall set sail straight from the break and kept on gamely to claim third place, a length and a quarter behind.

However, this was to be the day for Ortensia, who was virtually retired at one stage but reinvigorated by Messara this year and started her campaign with victory in the Al Quoz Sprint in Dubai.

And the decision to keep her in Britain for the rest of the summer has paid handsome dividends. She could even bid to follow up in the Betfred Sprint Cup at Haydock on 8 September.

Messara said: "It's fabulous. It's the most amazing feeling. To win a big one over here is a huge thrill.

"I couldn't believe it yesterday when it poured down. I thought we were coming here with no chance.

"I walked the track this morning and remained pessimistic. I thought it would be too soft for her.

"She needs top of the ground as she has tremendous acceleration. I just thought it was too soft for her to show her acceleration.

"I've made three trips from home and every time it has rained while I've been here.

"At one stage I thought we should have stayed at home, but we've stuck it out and she'll probably go to Haydock as long as she comes out of the race fine.

"After that she'll probably go back to Australia and we might bring her back to Europe next year. It's possible we might come back but she's a seven-year-old mare. You can't go on forever.

"If she can keep this going, we'll keep her going.

Buick said: "It's fantastic, I don't know how she won, to be honest.

"They went very fast and I was a long way back, but I could hold a straight course the whole way and she's so much better when she doesn't have to be switched in or out.

"You could see the way she finished the race she's got so much speed and I think if she steps back up to six (furlongs) again, she'll be very hard to beat.

"I don't think I've been quicker in a race before and they just got her off the bridle, but when she gets to the furlong and a half marker, she hits that sixth gear and picks up well.

"The ground is a little bit loose, so that probably didn't help her early on - we were kind of wheelspinning a bit.

"She showed at Goodwood what she can do to these sprinters and she showed today she's superior to the sprinters over here."

Spirit Quartz's trainer Robert Cowell said: "He's run his heart out and he's going to be a very exciting five-year-old next year now he has learned how to sprint.

"We must have made up a few pounds on the winner on that performance and half a furlong out I thought we might win, but (Ortensia) was making up ground hand over fist.

"The Prix de l'Abbaye might be our next port of call and I might give him a break and not take him to Dubai, so we save him for next season."

Provided the ground is quick enough, the other 7-2 joint-favourite Bated Breath will renew rivalry with Ortensia at Haydock after finishing sixth.

"Yep too slow for Bated Breath. He just can't quicken on that ground, Haydock next in two weeks hopefully he will get some fast ground," tweeted his trainer Roger Charlton.