Imported galloper Kings Will Dream has earned a ballot exemption into the Caulfield Cup by spacing his rivals in the Mornington Cup.

Irish-bred Kings Will Dream remains unbeaten in Australia with his win on Saturday and extended his winning streak to five since being purchased by his Australian connections and transferred to master trainer Darren Weir.

Ridden by Dean Yendall, Kings Will Dream was sent off the $2.10 favourite before beating Harrison ($9) by five lengths with Fastnet Dragon ($14) 1-1/4 lengths away third.

Saturday's victory completed a magic 24 hours for Weir.

He won the Group One William Reid Stakes with Hellbent at Moonee Valley on Friday night and collected a treble at the Golden Slipper meeting at Rosehill, including the Group One Ranvet Stakes with Gailo Chop.

A feature double came his way at Mornington, where Stellar Collision won the Listed Hareeba Stakes before Kings Will Dream's victory.

Weir said Kings Will Dream would now be spelled to concentrate on the Melbourne spring carnival.

"He could continue racing, but it's job done now," Weir said.

"He deserves his rest and it's all about the spring.

"The preparation has turned out great.

"When we started in a benchmark 64 I wasn't thinking we were going to be winning a Mornington Cup.

"He was strong through the line at the 2400 metres which was great to see."

Weir paid tribute to his staff for the work they poured into the gelding, who was jumping from an 1800m win at Flemington to Saturday's 2400m success.

"It's not ideal but if they're sound you can get the work into them to do it," Weir said.

"We've got the facilities to do it but I would have rather had a run at 2000 metres than doing it on the track at home."

Yendall said Weir and his staff had produced a great training performance to have Kings Will Dream progress from a restricted race at Warrnambool in January to being a Mornington Cup winner and in contention for a Caulfield Cup.

"This is basically his first preparation," Yendall said.

"I rode him at Warrnambool about eight weeks ago over 1200 metres and on his fifth start in Australia he wins the Mornington Cup.

"It's a massive effort."