Trained by Chris Waller as was his sire Zoustar, Zousain started six times last season for two wins and two seconds winning the Group II BRC Moet and Chandon Stakes and finishing second to The Autumn Sun in the Group I BRC JJ Atkins Stakes.
A $400,000 Magic Millions purchase for David Redvers/Mulcaster Bloodstock, he has already won over $330,000 for his current owners including Qatar Bloodstock, who share in the ownership of Zoustar.
"Physically he's a stunning colt and is the most like his sire and grand-sire that I've seen," said Antony Thompson.
"He's done enough at two and his form last season was very similar to that of Zoustar, who came out at three to win the Group I Golden Rose and Coolmore Stud Stakes.
"We're delighted to become involved with Zousain along with Glenlogan Park and RIFA Mustang with the ultimate plan of retiring him to stud at Widden alongside his sire."
Zousain is resuming from a spell in the Group II ATC Run to the Rose over 1200 metres and faces a field of 13 including unbeaten Star Witness colt Graff.
Zoustar finished fourth in this race before winning his next three starts – G1
Golden Rose, G2 Roman Consul and G1 Coolmore Stud Stakes to be crowned Champion 3YO Sprinter.