The 5yr-old Sundon mare will be flown to Australia on Tuesday.
She was trained for her win by Bruce Hutton, of Greendale.
Carmelasoprano had been placed in her previous three starts for Michael Taranto and Troy Smith.
Butterworth has raced several horses.
He met success with the former Gore trotter Tamra Dawn, who is now in the United States.
Lord Burghley, the nine-win trotter, was recently consigned to the US.
He will be raced by his Wellington owner Reg Caldow with Meadowlands trainer Chris Ryder.
Lord Burghley had his first three wins for Ian Cameron.
Caldow and Ryder had good success in the US with Golden Blend.
The former Hutton-trained trotter Rhythm Of The Night had been placed in his five starts in America.
Hutton consigned eight horses to American clients this week.
They included First Royal, Costalot, Poderoso, Albert Hall and Blazing Chapel.
First Royal has been bought by long-time client Al Carter, of Wilmington.
First Royal has won two races this season from the West Melton stable of Robert Dunn.
The Live Or Die 5yr-old won six when trained by Greg Hunter at Mataura Island for his father, Ossie.
Costalot won eight races from the Tony Herlihy stable.
Sea King won first up last night.
The 3yr-old is trained by Dean Taylor for David Will, of Temuka and his sister-in law Judy Dillon, of Ardlussa (northern Southland).
Will was in the syndicate that won five races with Dreamy Chick from the Taylor stable.
Mrs Dillon races Jimbob Jac (seven wins).
She is jogging Jimbob Jac, who was spelled at the end of April.
Sea King, a yearling sales purchase, is a half-brother to Pacific Rocket to Lady Of Grace (four wins).
Sea King was one of three successive wins in a row for reinsman Mark Jones.
Flyin Ferrari, winner of the graduation final last night, is a family affair.
He is raced by breeders Janice Marshall, of Wangaloa with her son Murray and daughters, Jackie Brash, of Invercargill and Marie Harris, of Melbourne.
A big 6yr-old, Flyin Ferrari was having his fourth start.
"He was very immature and has been in a fence and pulled a muscle in his back, which has delayed his racing career," Mrs Marshall said.
Flying Ferrari is by Sands A Flyin and the first foal of Femme Ferrari.
She won three races for the Marshalls when trained by Hamish Hunter, who has Flyin Ferrari.
Rathbone was a late scratching last night when found to have an elevated temperature and heart rate.
