Boom colt Royal Symphony has produced a stunning finish to overcome difficulties and remain unbeaten in his highly anticipated spring return at Flemington.

The Tony McEvoy-trained colt was awkwardly placed back in the field on the rail in Saturday's Listed Pin & Win Plate (1400m) and only managed to weave into the clear inside the final 150m under jockey Dwayne Dunn.

Once clear, he launched late to chase down Eclair Sunshine ($61).

It's was the colt's fourth-straight win and he tightened his grip on Caulfield Guineas favouritism, firming from $4.60 to $3.

"That was very special," McEvoy said.

"I nearly did the old 'can't win' (call).

"And Dwayne just peeled his way through the field and the way he picked up late was things that special horses do."

Royal Symphony, backed from $2.20 to $2 favourite, got home by a head over the Adelaide visitor Eclair Sunshine with another 1-1/2 lengths to Sebfire ($18) third.

McEvoy believes there's improvement in the colt and will decide whether his next start is the Bill Stutt Stakes over 1600m or the Guineas Prelude over 1400m before his main aim of the Group One Caulfield Guineas (1600m) next month.

"I wanted him ready to win today because I wanted to protect his record," McEvoy said.

"But I didn't want him peaking today. He'll peak in mid-October."

Royal Symphony didn't muster speed early then Dunn said the colt struck trouble early in the race.

"He nearly clipped heels and crashed," he said.

"To his credit he put up with that. I just had to ride for a bit of luck and when the luck came I just had to hope he accelerated, which he did.

"Good horses get you out of trouble."