Authentic won the $6 million Breeders' Cup Classic as Bob Baffert capped a troubled 2020 with two victories at Keeneland, where European raiders won all four turf races on Saturday in sometimes sensational style.

Baffert's Kentucky Derby winner Authentic was a wire-to-wire winner in the Classic under John Velazquez, cruising to his third Grade One victory over elder stablemate Improbable in the marquee event of the 14-race, $30 million Breeders' Cup slate at the Keeneland track in Lexington, Kentucky.

There were no fans in attendance, but the coronavirus pandemic didn't stop a determined contingent of more than two dozen runners from Europe, who came up big on Saturday after being shut out in Friday's five races.

Order of Australia, a 73-1 longshot who was in the $2 million Mile only after One Master was scratched because of injury, led a sweep of the board for Irish trainer Aidan O'Brien under jockey Pierre-Charles Boudot - who was only aboard because Christophe Soumillon tested positive for COVID-19 during the week.

Boudot made the most of his chance, grabbing his second win of the day after piloting Audarya to victory in the Filly & Mare Turf - a mount he inherited after Ioritz Mendizabal was unable to make the trip from Europe because of a positive coronavirus test.

"It's just unbelievable," Boudot said. "It's a dream come true for me. It is my first win during the Breeders' Cup week with Audarya.

"I had an opportunity ­because Ioritz had a positive test of COVID and his trainer give me this fabulous mare and today she makes her perfect job.

"A chance again because One Master is non-runner and Christophe had a positive COVID test again and I pick up this ride."

Order of Australia broke from the outside post and was running second entering the final straight, where he overtook Halladay and held off the late-charging Circus Maximums. Lope Y Fernandez finished third to complete the sweep for O'Brien.

O'Brien wasn't in attendance in Lexington, but his 13th Breeders' Cup win, and his first in the Mile, was a welcome reversal of fortune after his English Derby winner Anthony Van Dyck was euthanized on Tuesday after breaking down in the Melbourne Cup.

That followed disappointment in October when O'Brien withdrew four runners from the Prix de l'Arc de Triomphe after contaminated feed put them afoul of anti-doping regulations.