Best Guess maintained his impressive preparation for Sydney's premier trainer Chris Waller by cruising to a commanding victory at Rosehill.

The four-year-old gelding stepped up to 1200-metres with ease in the Jaydub Electrical Handicap, winning by 2-1/4 lengths.

Best Guess, the $2.30 favourite, is yet to finish worse than third since returning from a spell.

"I think the distance suited and I think he will get a bit further," said Waller's racing manager Charlie Duckworth.

"I was a little bit concerned the track might have been a little bit too firm for him but obviously he has done the job very easily."

Star Reflection ($7.50) led the chasers while Pipeline ($6.50) was a half-head third.

"He' s a very fast horse but he's also an absolute gentleman," Duckworth said.

"A lot of sprinters can be wound up but he has a beautiful temperament and does exactly what is asked of him."

Shinn was impressed after riding Best Guess for the first time.

"He had tactical speed drawing one and I put him straight there. He led, dominated the race and was too good."