Two Australian Bloodstock-owned imported horses have given trainer Darren Weir and apprentice Ben Allen a race-to-race double at Caulfield.

Big Duke took out Monday's Dennis Hanrahan Handicap before Plein Ciel won the Allan Wicks Handicap.

They may have been restricted races but the pair both indicated better wins are in store.

Plein Ciel, a German-bred four-year-old, came to Australia a maiden before winning first-up Warrnambool and then backing it up with a Sandown victory.

Sent out $1.65 favourite on Monday, Plein Ciel scored by 3-1/4 lengths with Weir suggesting there was improvement to come.

Weir said Plein Ciel was laid-back at home but when taken to the trials and presented in the parade ring, could become a handful.

"It's time to step up the work a little bit and get his manners in shape," Weir said.

Plein Ciel was ridden contrary to his usual pattern after drawing the widest barrier and Weir thought he may have vulnerable.

"On the corner I thought 'this will test you out' but he stretched out great late," Weir said.

"Hopefully he'll find himself in a nice race at some stage as we step him up in distance and grade."

Big Duke was sent out $3.50 favourite in his 4-1/2 demolition job of a benchmark 78 class race at his third Australian start.

Weir said he had noticed a big change in the Irish-bred five-year-old.

"Things weren't easy for him," Weir said.

"He didn't want to do the work and wanted to jack up and I thought he didn't race properly in his first two starts.

"He's a lot more relaxed now and paraded a lot better and raced a lot better today and he showed the further he gets the better he's going to be."