It was the seventh win for the season for the 4yr-old mare, trained by Cran Dalgety for Murray Boyd, of Kaikoura.
She has amassed $85,235 in stakes in 20 starts since October.
She has won a total of 14 races and $183,170.
Boyd also races Bettors Creek from the Dalgety stable.
The 3yr-old Bettors Creek has won eight races and $70,045 this season. Bettors Creek has been campaigning in Auckland and won there on June 8, the same night as Donegal Delight was successful.
Both horses are by Bettor's Delight.
Boyd operates Donegal House, a licensed accommodation venue.
His horses now race in lime green colours with an orange donegal logo.
Donegal Delight is set to wind up the season in a free-for-all at Addington on Friday week.
"She will be aimed at the Kaikoura Cup in October in view of where she is owned," Dalgety said from Honolulu where he is on holiday with his family.
It was the second Rangiora Winter Cup win for Dalgety and reinsman Dexter Dunn.
They combined to win the race with London Legend, who started from a 30m handicap in 2008.
The race has been won from a handicap seven times since it was run from a standing start in 2005 with Bondy, the 2009 winner, also starting from 30m.
Dalgety and Dunn also won yesterday with Bit Of Legend. It was the second win for the 2yr-old in six starts.
Dalgety is second in the premiership with 95 wins this season. Dunn is the leading reinsman with 174.
Dalgety advised stewards that Franco Harrison was found to have a foot infection after he finished sixth as favourite at Addington on June 22.
The horse has been treated and will have a short spell.
Mark Purdon continued his success in Australia when he won with Border Control and Cyclone U Bolt.
Border Control won a semi-final of the Vicbred series at Melton on Friday night in a 1.58.8 mile rate for the 2240m (mobile).
He won by a neck from Major Star.
Cyclone U Bolt won a heat of the Victoria Trotters Derby at Cranbourne on Saturday night.
Tower Of Song, Biddy Bid and Majestic Kenny were stood down until giving one satisfactory trial after they raced yesterday.
Jonny Cox was fined $200 for excessive use of the whip on Valhalla at Forbury Park on Friday night.
Hay List, the well-performed sprinter, has undergone stem cell surgery on his injured knee, AAP reports.
Hay List fractured his leg in April.
The injury occurred when he was having surgery for colic.
He has had fat removed from his tail and injected into his knee.
The liposuction procedure involved extracting dormant cells that can repair muscle and tendon.
