Glen Boss says he will be riding the right horse in the Cox Plate after New Zealander Ocean Park completed a hat-trick of Group One wins in the Caulfield Stakes.

Ocean Park, who turned four on Saturday, backed up from victories in last month's Mafki Challenge in his homeland and the Underwood Stakes to underline his Cox Plate claims.

"He's got weight-for-age form," Boss said.

"I'm not underestimating the job he's got ahead of him but at the moment I wouldn't swap, I really wouldn't.

"He's got the ability to put himself anywhere in the race."

Ocean Park, the $1.50 favourite, defeated Alcopop ($20) by three-quarters of a length with Sincero ($5) a nose back third.

Boss said he was supremely confident of Ocean Park's chances in the $3 million Cox Plate at Moonee Valley on October 27.

"I think he's the right horse, I really do," Boss said.

He said Ocean Park's Caulfield Stakes hit-out would provide the perfect lead-in.

"That's a race he really needed," he said.

"He's actually put on weight since that last run (in the Underwood Stakes) so today's run was one he really needed to clean him right out.

"I'm glad he had a contest today because he needed it but the best part about it was his attitude.

"He put himself in a very good spot very easily and in the run I couldn't believe how relaxed he became."

Michael Rodd said perhaps Sincereo would benefit from blinkers after he loomed up and looked as if he would challenge the winner.

"I got beaten fair and square by the winner but I still think my bloke's got some improvement," Rodd said.

"I think we need to go for a set of shades to sharpen him up a bit. He gets lackadaisical when the sprint goes on."

In contrast Boss said Ocean Park responded to his urgings without fuss.

"For a horse who's had not a lot of racing he's got a very, very good brain in the race," he said.

"He does exactly what you want and as soon as I asked him to come on by about the 600 (metres) he got interested in the race.

"When he got clear he switched off, but that's probably because he just needed the run."

Dominic Tourneur said comeback galloper Alcopop still had improvement and was unlucky not to have finished closer.

"I'm not convinced he was 100 per cent out there today," Tourneur said.

"Having to come off Sincero at the top of the straight probably cost us a long neck. If that hadn't have been the case it may have been interesting