John Sadler is convinced Charmed Harmony's best chance of continuing his winning streak is by dictating from the front.

But the trainer fears the presence of several on-pace rivals in Saturday's Group One Sir Rupert Clarke Stakes (1400m) at Caulfield could play against the chances of his horse claiming a fifth-straight win.

"The only thing is that it looks like we're going to get a dry track, which is not in his favour, and he's going to go forward and probably lead and there'll be quite a bit of pressure on," Sadler said.

"But whatever will be, will be.

"He's earned his crack at it and we'll see how we go.

"But I'm really pleased with the horse. He's going terrific."

Charmed Harmony has been in a rich vein of form, winning his past four starts in 1400m Open Handicaps.

Sadler was looking to give the horse his chance in the Memsie Stakes last month but Charmed Harmony didn't gain a start and instead claimed a convincing win in a race on the undercard.

"He's been able to win those races because he's run them into the ground. This level is going to be a lot harder," Sadler said.

"That would give him his best chance, if he goes forward and leads and can get his own way.

"If he doesn't, well he's going to be in trouble but the horses that go with him will be in trouble also."

The Sir Rupert Clarke Stakes has attracted a full field of 18 plus four emergencies.

The Lee and Anthony Freedman-trained Disposition is favourite at $3.40 and has barrier three with Damien Oliver to ride.

Under The Louvre, twice a placegetter at Group One level last campaign including in the Oakleigh Plate at Caulfield, is at $6 with Memsie Stakes placegetter Stratum Star at $7.50.

Stratum Star and topweight Lucky Hussler ($10) are trained by Darren Weir who won the race last year with Trust In A Gust.

Charmed Harmony is at $11 with Ben Melham booked for the ride.