Jockey Dan Griffin put a family tragedy to one side to partner Magic Millions contender Dieters to an impressive debut win at Doomben on Saturday.

Griffin rode with a heavy heart after revealing his uncle Ronald Griffin died in a car accident at Peak Crossing, near Ipswich, on Thursday.

"It's been an emotional week losing my uncle but he was riding with me today," Griffin said.

Trainer Jason McLachlan was supremely confident of victory in the Coca-Cola Amatil Plate (1050m) with Dieters.

"I've had a massive opinion since the first time I galloped him," McLachlan said.

"I had my biggest bet on him today since Planet Ruler won his Maiden."

Planet Ruler was an outstanding sprinter for McLachlan's father Bruce, winning 10 races in a row from September 1987 until his colours were lowered in the 1988 Stradbroke Handicap when he finished third to Campaign King.

McLachlan said Dieters, which cost $100,000, will have a short break before being prepared for the Magic Millions (1200m) at the Gold Coast in January.

The colt is by Written Tycoon who had a bonanza start to the season after also siring Capitalist, an impressive winner of the Breeders' Plate at Randwick 10 minutes earlier.

Also Magic Millions-bound is Rare Occurrence who ran 1.01 seconds faster than Dieters when she won the Coca-Cola Life Plate (1050m).

"She's not overly big but what she lacks in size she makes up for with toughness and natural ability," trainer Stuart Kendrick said.

Rare Occurrence impressed jockey Matthew McGuren with her determination to win by a head in a three-way finish from Fallen For You ($6.50) with the favourite Spot The Diff ($3.40) a half head away third.

"She copped two or three whacks over the head from the whip of Brad Stewart on the runner-up so she's a real bulldog," McGuren said.