Rule of Law won in a thrilling finish from Quiff to give the Godolphin team their fourth St Leger winner.
McEvoy celebrates his Classic win on Rule of Law
The horse, ridden by Kerrin McEvoy and trained by Saeed Bin Suroor, took up the running after three furlongs and held off fellow joint favourite Quiff at the finish.
Quiff, ridden by Kieren Fallon, was bidding to become the oldest filly for 12 years to win the world's oldest Classic.
Tycoon, a 9-1 shot ridden by Darryll Holland, came in third.
McEvoy became the first Australian since 1969 to win racing's last Classic of the season.
This is his first season racing in Europe and the win came just six days after he landed his
first Group One victory in Europe on Warsaan in Germany.
"This is right up there with my Melbourne Cup win. What a way to
cap my first season here, to win a classic in what's a foreign
country to me," McEvoy said.
Rule Of Law was smartly out of the stalls and was soon disputing it up front
with Mikado as the nine runners set out at a slow pace.
As McEvoy slowly wound up the pace from the front, the field became strung
Fallon was in a prime position on Quiff sitting in about third place
most of the way round, and turning for home he looked ready to challenge.
However, Quiff could not find a clear path through and Fallon was forced to
switch, losing valuable momentum as Rule Of Law streaked ahead.
The filly collected herself well but she just could not find enough extra
while Tycoon, who had hunted round at the back of the pack, accelerated through
the fading runners to claim third.
Quiff's trainer Sir Michael Stoute has yet to win the Doncaster Classic, and
he also had the fourth-placed horse Maraahel.