Melbourne's first weight-for-age race of the season has produced a thrilling contest with the ever-improving Mourinho edging out Tasmanian gelding The Cleaner in the P B Lawrence Stakes.

And Mourinho's victory in Saturday's Group Two Caulfield feature has provided trainer Darryl Blackshaw with his biggest win after 40 years in the game.

Blackshaw has taken over the training of Mourinho and more than a dozen other horses while fellow Moe trainer Peter Gelagotis serves a three-month suspension for a raceday treatment breach stemming from May.

Mourinho didn't gain a start in the Cox Plate last year but connections are hoping he can earn his way into the weight-for-age showpiece this spring.

In his season return, the eight-year-old emerged to challenge frontrunner The Cleaner ($10) in the straight and the pair staged a gripping battle with Mourinho ($8) getting home by a nose.

They are expected to clash again in the Dato Tan Chin Nam Stakes at Moonee Valley, a race in which The Cleaner denied Mourinho last year to earn a Cox Plate berth.

Former Hong Kong galloper Dibayani ($6.50) finished a length away third at his Australian debut while Big Memory ran home strongly for fourth.

Stewards reported a post-race scope of unplaced favourite Smokin' Joey detected an exercise-induced bleed.

Blackshaw suspected Mourinho was going well but he wasn't sure how well as Saturday was the horse's first start for him.

"I haven't had him that long but the foreman has been there the whole time and he reckoned he was right," Blackshaw said.

"It's exciting, it really is."

Mourinho will be in Blackshaw's care for one more start in the Dato on September 5 before Gelagotis' suspension finishes.

Regular rider Vlad Duric was full of admiration for Mourinho, as well as the runner-up.

"I thought I was going to beat The Cleaner by half to three-quarters of a length and in the end I was struggling to hold him off," Duric said.

"He's just a great horse, the second horse."

Duric expects Mourinho to take great benefit from the race fitness-wise.

"I'm really looking forward to his next run in the Dato and his run after that, then hopefully all going well we go into a Cox Plate with a horse that loves Moonee Valley and deserves his chance," he said.