"I know he only finished fifth at Ashburton [on Monday] but they don't come home much faster than he did.
"He ran on really well and is very fit now. And I am happy with how Zac [Butcher] has been driving him because I think that is how he goes best, following the speed."
Sky Major remains the second favourite for the Cup behind Smolda, with three potential market impacters next week -- the Kaikoura Cup (Monday), the NZ Cup draw and the Cup trial both on Wednesday.
Purdon also has Lancewood Lizzie in the Cup and the pair could be joined at Addington by three of their stablemates who race at Alexandra Park tonight.
Kimani and Can't Refuse tonight contest what looks like a mini Sires' Stakes Final dress rehearsal before the actual final on November 10, with five of tonight's six starters Addington bound.
There is little between the Purdon pair and Shandale, Art Form and Motown, suggesting luck in the running could decide the race of the night.
"I suppose I might narrowly opt for Kimani as the better of our two hopes but Can't Refuse was very good beating most of these last start. So either could win without surprising me."
Shandale was a booming second to Can't Refuse last time they met, with Motown cruising when he broke in the trail in the same race.
Add in Art Form, who was beaten by a class act in Express Stride last Thursday, and race four tonight looks one of the mini highlights of the Alexandra Park season so far.
Leanne's Boy can seal his trip to Christchurch with a good performance in tonight's main trot, where his 20m start over backmarker Prime Power could be a crucial difference.
"He galloped early when trying to go too fast for himself last start but on the whole I am very happy with the way he is going," said Purdon.
"We are still considering the Dominion [November 13] so I expect him to go well this Friday."
Friday's three
Best bet: It's Oscar (Alex Park, R7): In great form and key rival is scratched.
Each way: Tereskova (Alex Park, R3): Speedy little mare ideally suited to rare 1700m mobile for the trotters.
Blowout: Motown (Alex Park, R4): Going well when he galloped last start. As good as these other star 3-y-os.