The mares, as they have for much of the season, look to be the key to today's $85,000 Windsor Park Stud Japan Trophy at Tauranga.
Diademe and Viadana make up a powerful duo in the group two feature.
Diademe has risen through the class ranks with lightning speed and in just eight starts has attained a 101 rating mark.
That puts her 1.5kg in front of Viadana and that might be significant in the closing stages of this race.
Viadana has won six races to Diademe's four and with luck that differential would be even greater.
Viadana got back and wide from an outside gate in the Westbury Classic last start and did remarkably well to finish as close as sixth in a race that was run quickly over the closing stages.
The start before she was ridden too aggressively in the Thorndon Mile and was run down after leading for the first half of the home straight.
She has a draw to suit this time and looks well placed. Diademe is the obvious danger.
Maximum Height is trying for six straight wins and it's difficult to know just how good he really is because for much of his career he looked as though he'd be way out of his league in this company.
Fleur De Lune is as gutsy as hell, but she is a small mare and with topweight of 59kg she might just struggle late in the race. She will be better off when she gets to the Breeders Stakes at Te Aroha on level weights.
Difficult to know what to make of Shuka (No3, R5). He's the winner of nearly a quarter of a million, but he hasn't won a race for 18 months, even though he has seconds in top class races. He keeps running races that get you in for his next start, but can find ways to get himself beaten. Difficult to leave him out of this and difficult to give him a strong push. This race should tell some stories going forward. Guns At Five (No2) is shooting for three straight and his determination should take him close.
Neo (No1, R3) was in great form in the spring until he got into a speed duel in the 2000 Guineas at Riccarton and faded out. He'd already bagged the Wellington Guineas and although he has plenty of weight today he should be difficult to hold out in his resuming run. He looked good winning a recent Cambridge barrier trial.
With Speech Craft scratched, Pussy O'Reilly (No3, R7) makes even more appeal to take her fourth victory today. She has made it tough for herself with her racing pattern lately and if she can stay even fractionally handier she should be tough to beat. Ididit (No9) has been freshened since failing at Trentham and could surprise.
A 4kg claim makes Art Beat (No4, R8) appealing in the open sprint. She goes well fresh and even with an inexperienced apprentice on her back she has sufficient finishing drive to swamp most of these late. The Hombre (No2) is the obvious danger. He will lead and be difficult to peg back. He is required to concede 7kg to Art Beat.
Beauty Perception (No3, R9) has been a late developing Zabeel 4-year-old who has been turning in solid staying performances. The small field will make it easier for him to pick many of these off late in the race. One Above (No2) is a threat.
Silent Achiever and Zurella are two New Zealand mares who can do us proud in Sydney this afternoon in the A$400,000 Ranvet Stakes and A$600,000 Coolmore Classic.
Silent Achiever is close enough to favourite at $3.80 in a race which will see her suited by jumping up to 2000m, but Zurella is at any old odds - $31 in many betting shops in Australia. She is a better chance than that.