Ardrossan and Bostonian had set down to fight out the finish before Harris guided Melody Belle into a gap at the 100m mark where she charged home to snatch victory by a head from Bostonian, with a nose back to Ardrossan in third.
Harris, who had worked and ridden for Te Akau Racing in his formative years, paid tribute to his former employers after the race.
"I'm thrilled to ride for Te Akau and Fortuna [owner] who have given me the opportunity," he said.
"I did my apprenticeship with Te Akau, so they have been good to me and I'm just rapt.
"Turning for home, I thought I was in a little bit of trouble, but then I got a suck up behind Jason [Waddell, riding Ardrossan], I gave her a couple and she just took off.
"She had me in two minds turning for home but when we got to the 200m, she clicked into gear and I knew we were in business."
Owned by the Fortuna Melody Belle syndicate, the victory was the third at group one level this season for Melody Belle, who has now won nine of her 18 starts and over $1.38 million in prizemoney.
- NZ Racing Desk