Charles and training partner Peter Corbett scored the biggest win of their training careers when stayer Dee And Gee bravely fought off all challengers in the straight to win the 3200m feature on Saturday.
The victory came four years after Charles was given 4½ months to live when diagnosed with brain cancer.
The horsewoman has so far beaten that devastating illness and she credits part of that to her team of horses.
"I don't know if I would have been able to get to today if I didn't have the horses," Charles said.
"I think I would have given up if I didn't have the horses - I would just be lost."
Charles was bursting with emotion when Dee And Gee held on bravely to win for rider Leah Hemi.
"It is enormous. I am so lost for words.
"She is a very tough horse and I am so proud of her. She has just given us so much pleasure."
Dee And Gee gained her first major cups win after running second in last season's Wellington Cup and fourth in the Auckland Cup.
The Darci Brahma mare broke through with the aid of a excellent ride from Leah Hemi.
Hemi gave the 6yr-old a perfect run in the one-one throughout the race, before asking Dee And Gee for an effort in the straight.
The pair quickly hit the front, but were open to being run down when a wave of finishers spread across the track.
Dee And Gee fought off all of her rivals for a tough victory by three-quarters of a length over runner-up Kaharau at the finish.
Wellington Cup winner Gorbachev was a head away from the runner-up in third.
Hemi was quick to point out it was Gorbachev who spoiled the Dee And Gee camp's Wellington Cup party when he nosed out the Canterbury mare earlier this year.
"She was really unlucky when Gorbachev got her at Wellington, but today she got him," the jockey said.
"She hasn't got a sprint at all but has a really high cruising speed that she can sustain for quite a while.
"I'm just so happy for Peter and Terrill and I know that Terrill will be so stoked."
Hemi's win came after she had helped sent other cup carnival spoils to the deep south.
The northern jockey won the only other staying event on the Riccarton card when riding Riviera Rock to win in rating 82 company over 2500m.
Like Dee And Gee, Riviera Rock fought hard under Hemi's urgings to win race 2 by a neck over Mondorani.
That result gave Mondorani a third runner-up placing at the carnival for trainer Kevin Myers.
Riveria Rock's win was the second leg of a Riverton-trained double after What's Up Alf won race 2.
The Kelvin and Aimee Tyler trained 8yr-old won in premier company over 1800m for rider Kin Kwo.
