Mataderos has chased Sundees Son home and pushed him close doing it on several occasions, most notably in the Dominion in November, and Dunn, part of the stable that trains both, says Mataderos gets his chance tonight.
"I think if he steps he will be hard to catch," said Dunn. "Sundees Son is the better horse but the gap between them has closed quite a bit and if he can reach the front I don't think [driver] Blair [Orange] will let up.
"If he does and my horse gets around and sits parked easily then Sundees Son is Sundees Son and I think he will be too good.
"But if Mataderos runs really hard then I don't want to be taking off and giving my horse a gutbuster the week before a Group 1 so we could end up giving him a decent start.
"With all that in mind, Mataderos gets his best chance to beat my horse this week."
The tempo and tactics could also decide the chances of Bolt For Brillance, who has been outstanding this season and will return south a better horse than the one Sundees Son and Mataderos beat so easily in the Dominion.
He has raw speed if he can get near the lead, and tracking Sundees Son in a one-one position, he could blow past both Dunn runners.
Tonight's pacing feature sees Pembrook Playboy taking a step closer to The Race at Cambridge on April 14, but facing a tricky inside second line draw over the 1980m mobile.
He may still get his chance in a race with plenty of gate speed and potential first-lap pressure.
The Addington meeting will hold centre stage as Alexandra Park continues to struggle for numbers and has attracted only six races, with the programmed open-class pace, one of the final lead-ups to The Race, being scrapped after it only attracted four entries.
That will see Self Assured, Mach Dan and Spankem have a trial before the first race to further prep them for the $900,000 slot race in just under a fortnight.