Epsom Derby winner Adayar and Irish runner Tarnawa are competing for favouritism for Sunday's 100th running of the iconic Prix de l'Arc de Triomphe after 14 horses stood their ground on Tuesday.
Adayar -- who will join English St Leger-winning stablemate Hurricane Lane in the line-up -- is due to be supplemented at a cost of 120,000 euros ($141,181) on Wednesday, along with star Irish filly Snowfall.
They will join a star-studded field which includes two from Japan -- Chrono Genesis and Deep Bond.
Chrono Genesis -- to be ridden by two-time British champion jockey Oisin Murphy -- is the better fancied of the duo to achieve the long-held aim of the Japanese racing fraternity to win the Arc.
Deep Bond, though, has attracted support after winning the Prix Foy earlier this month.
However, English outsider Mojo Star -- second behind Adayar in the Derby and also to Hurricane Lane in the St Leger -- is uncertain to take his place at Longchamp.
Adayar inflicted Hurricane Lane's sole defeat in the Derby and is bidding to become the seventh Epsom winner to triumph in the same year since the legendary Sea Bird in 1965.
However, 20 others have fallen short in the same period.
Tarnawa had shot to favouritism following her impressive runners-up spot in the Irish Champion Stakes on September 11 and won twice at Longchamp last year.
Nevertheless, the Charlie Appleby-trained Adayar -- who is the chosen mount of owner Godolphin Operation's first-choice stable jockey William Buick -- has replaced the Irish mare as favourite with some bookmakers.
Hurricane Lane has earned his place in the field due to impressing Appleby on the training gallops, showing no signs of fatigue since his win in the St Leger on September 11.
He will make history if he does prevail as no St Leger winner has gone on to win the Arc in the same year -- Ballymoss did but in different years.
"We're excited, with this being the 100th Arc, having two colts going into it with the profiles they have," said Appleby.
Appleby's only worry regarding Hurricane Lane -- named after a storm that hit Hawaii in 2018 -- is if no rain comes.
"There is a bit of rain forecast during the week, and that will suit us," he said.
"The only negative I can give regarding Hurricane Lane's participation is were it to become fast ground.
"That would (then) be a discussion that would have to take place nearer the time."
Snowfall -- who won the Epsom Oaks by a record 16-length margin in June -- suffered a surprise defeat on her last outing in the Prix Vermeille at Longchamp but trainer Aidan O'Brien has indicated he will supplement her.
She will join stablemates Love and Broome.
O'Brien will hope this year's Arc is a happier affair than 2020 when he had to withdraw his four runners due to an illegal substance in their feed.