Tarnawa has a chance to propel Dermot Weld into exclusive company in Sunday's Qatar Prix de l'Arc de Triomphe but the Irishman has pointed to another five-year-old mare as a major threat.
Weld nominated the Japanese mare Chrono Genesis as being as big a danger to Tarnawa as any of the European classic winners due to line up in this weekend’s 100th renewal of the €5 million feature.
Europe's most coveted all-aged race currently has 14 horses left in although both the Epsom Derby and Oaks winners Adayar and Snowfall are expected to be supplemented on Wednesday at a cost of €120,000 each.
Snowfall is set to be Aidan O'Brien's number one shot at a third Arc success with Ryan Moore on board, with both Love (Frankie Dettori) and Broome also in the mix for Paris/Longchamp.
O’Brien has won the Arc twice before with Dylan Thomas in 2007 and Found who led home an unprecedented Ballydoyle 1-2-3 in 2016.
In the past back to back wins for Alleged (1977-78) contributed to Vincent O'Brien's tally of three Arc victories, while John Oxx was successful with both Sinndar (2000) and Sea The Stars in 2009.
The only other Irish-trained Arc winner was Levmoss for Seamus McGrath in 1969, so Weld has a shot at becoming just the fifth Irish-based trainer to join one of world racing’s greatest rolls of honour.
The Arc's lure for Japanese racing in particular means two challengers will try to finally win it for Japan.
Deep Bond is set to be one of the outsiders, but Weld is not alone in thinking Chrono Genesis, the mount of Oisin Murphy, is likely to be a leading player.
Chrono Genesis won her last start at Group 1 level in Japan in June, prior to which she was runner-up to Mishriff in the Sheema Classic at Meydan.
Despite support for Adayar in ante-post betting on Monday, Tarnawa remains towards the top of the betting, although Weld insisted it is a wide open Arc this year.
“I reiterate with everybody, in my opinion it’s a very open Arc. I see it clearly as a very open race,” he said.
"Japan, as a country, probably has its best chance ever of winning the race. She (Chrono Genesis) is a very high class mare, and I think she could be every bit as difficult to beat as the classic winning colts from England, " Weld added.
El Condor Pasa was only just beaten by Montjeu in the 1999 Arc, while Nakayama Festa (2010) and Orferve (2012 & 2013) were also runner up.
Japanese racing’s most famous runner, Deep Impact, was third in 2006 before being disqualified.
Finally landing the Arc has turned into something of a national obsession within Japanese racing but the significance of France’s greatest race is immense too closer to home.
“It would be wonderful if she (Tarnawa) could achieve it,” Weld admitted on Monday. “I’m happy with her overall, satisfied with her preparation and we go into a very open race.”
It is 40 years since international racing's renowned pioneering figure tried to win the Arc with his dual-Oaks winner Blue Wind. She failed to fire at Longchamp when only 15th to Gold River, while the 1996 Irish Derby winner Zagreb was 13th to Helissio that year.
The four-time Irish Leger hero Vinnie Roe finished an honourable fifth to Dalakhani under the late Pa Smullen in 2003, while Harzand was out of the money in 2016.
Harzand memorably broke Weld’s duck in the Epsom Derby five years ago and another Aga Khan-owned star is now on the verge of doing the same in European’s racing’s other supreme prize.
With significant rain forecast for Paris later this week, Tarnawa’s versatility in terms of ground may emerge as a significant plus to her chance.
She landed the Prix de l’Opera on heavy going on last year’s Arc programme yet subsequently won on firm ground at the Breeders Cup.
In other news Aidan O'Brien's 1,000 Guineas winner Mother Earth could head a sizable Irish challenge into Saturday's Kingdom of Bahrian Sun Chariot Stakes at Newmarket.
Unlucky when third to Jessica Harrington’s No Speak Alexander in the Matron Stakes over Irish Champions Weekend, Mother Earth may clash again with that rival in Saturday’s mile Group 1.
They are among half a dozen Irish-trained fillies still in the mix of 17 entries left in the Sun Chariot after Monday’s acceptance stage.
Mother Earth’s stable companion Empress Josephine is joined by Johnny Murtagh’s Champers Elysees, Epona Plays (Willie McCreery) and Shale from Donnacha O’Brien’s yard.
Alcohol Free and Snow Lantern are set to lead the home defence of a race which the Ballydoyle team won back to back in 2016-17 with Alice Springs and Roly Poly.