Champion Australian thoroughbred Winx took a big step toward knocking American horse Arrogate from the top of the world rankings on Saturday by easily winning her 21st straight race in the Group 1 Turnbull Stakes at Melbourne’s Flemington racetrack.

Ridden by her regular jockey Hugh Bowman, the six-year-old mare trounced her six rivals in the 2,000-metre (1-1/4 mile) event, one of the key early races in Melbourne’s lucrative spring racing carnival, winning by six-and-a-half lengths.

The 300,000 Australian dollar (US$233,000) first prize took Winx’s earnings to 13.7 million Australian dollars (US$10.7million) second on the all-time Australasian list behind three-time Melbourne Cup-winning mare Makybe Diva.

“She’s a brilliant horse. Whatever you ask her to do she does,” said Winx’s trainer, Sydney-based expatriate New Zealander Chris Waller. “She makes us all look good. There’s no training manual for a horse like Winx.”

Winx — who may be bound for England’s Royal Ascot next June — is already at very short odds to go to the top of the Australasian money list when she attempts to become only the second horse to become a three-time winner of Australia’s greatest weight-for-age race, the W S Cox Plate (2,040 metres), at Melbourne’s Moonee Valley course on October 28.

Victory there would likely also send Winx to the top of the World Thoroughbred Rankings (WTR), compiled by the France-based International Federation of Horseracing Authorities.

Already the top-rated horse on turf, Winx was given a rating of 132 in the most recent set of WTR figures, just two points behind dirt champion Arrogate, the Dubai World Cup winner earlier this year. However, recent patchy form from the American galloper is expected to result in Winx taking his number one position when the next rankings are released on November 9.

Though a horse of fairly unremarkable appearance, Winx has now won 25 of 31 career starts, from 1,100 metres to 2,200 metres. The bay mare’s career began in relatively moderate fashion, with wins in just four of her first 10 starts. However, she won again at her 11th start, in Queensland state, in May 2015, and has not been beaten since, with 13 of the 21 successes coming at the top Group 1 level.

Only 11 horses in world history have won more successive races, several of them in lower-level racing jurisdictions and against less than top quality opposition.

One notable exception was another champion Australian mare, Black Caviar, who twice earned a world’s-best rating during a career in which she was unbeaten in 25 starts, including one at England’s Royal Ascot in 2012.

Kincsem, a Hungarian mare who raced in the 1870s, was unbeaten in 54 starts, while Puerto Rica’s Camarero won 56 straight — in a career featuring 73 wins from 76 starts — in the 1950s.