She held off the strong-finishing Beaudiene Bad Babe by half a head.
Lauraella is the first filly to win the Great Northern Oaks-Sires' Stakes final since Tupelo Rose in 2001.
It was her fifth win on end and eighth from 10 starts this season for earnings of $417,068.
The New Zealand Oaks on Friday night and the Harness Jewels on May 30 are remaining rich opportunities for Lauraella, trained by Geoff Small for the Hardwood syndicate comprising breeders Sandy and Jan Yarndley and Max and Judy Hunter, of Cambridge.
The daughter of Christian Cullen and Black Maire has justified their decision to decline $75,000 when she was offered at auction as a yearling.
• Phil Burrows, who returned to training in his own eight months ago, produced Continental Auto to win the $60,000 Sires' Stakes Final for 2yr-old trotters on Saturday.
Continental Auto prevailed by a nose from The Fiery Ginga, who staged a phenomenal effort after losing some 60m in the early stages.
He left stride at the start and he was hampered by another horse soon after.
His trainer-driver, Alan Clark, was subsequently fined $300 for excessive use of the whip.
"He just got his head around sideways at the start and got a bit keen," Clark said.
The Fiery Ginga raced at the Timaru meeting 21 hours later and finished second after leaving stride at the start.
He ran Kowhai Ford to three-quarters of a length.
Kowhai Ford is bred on the same cross as Continental Auto.
Burrows re-established his own stable at Fernside after working for Nigel McGrath for several years.
He held the licence for the McGrath stable for 13 months from 2005 and trained 30 winners during that time.
Burrows helped break in Continental Auto at the McGrath stable after she had been withdrawn from the yearling sale.
She was bred by Mike Gourdie and Michael House.
She is by Continentalman from Autobank, an unraced half-sister by Sundon to Inda Bank whose 10 wins included the Cambridge Flying Mile and Rosso Antico Stakes.
Burrows took up the option to lease the filly then sold her to stable patrons Ron and Marie Dawe.
Burrows is training from their property.
"She was very narrow in front but I liked the way she worked and felt she had some trotting blood behind her," Burrows said.
Ron Dawe had young horses The Big Mach and BG Three whom he sold unraced in 2007.
The Big Mach has since won four races from the Tim Butt and Phil Anderson stable.
Dawe claimed Striking Dash for $3500 in June.
The 7yr-old was transferred to Burrows and won his next start at Addington.
