The Wanganui open handicap was the first win as an apprentice jockey for Riddell, who had previously recorded four wins as an amateur.
"I'm just so happy to get this win, because it's taken a couple of weeks," said Riddell, a daughter of Group One-winning jockey Jonathan Riddell and former jockey and trainer Trina Marshall.
"I'm so glad to get and especially on Flash, who's one of my favourite horses in the (Kevin Myers) stable. It's extra special that the first win came on one of Kevin's horses. I can't thank him enough for giving me a go and taking me on as his apprentice."
Riddell's 9lbs claim reduced Verry Flash's 132lbs topweight to 123lbs in Saturday's $50,000 feature, and the 10-year-old enjoyed a comfortable run in midfield as Faustian Bargain and What A Charma set the pace.
The field bunched right up coming down the side of the track, giving Riddell a few nervous moments as Verry Flash was full of running but struggling to find room.
But Riddell found clear air in the straight and allowed Verry Flash to take care of the rest. He surged through on the inside of Sacred Pearl, who had swooped into the lead around the turn. It developed into a two-horse war down the straight, with Verry Flash digging deep and edging away in the last 0 to win by a length and a quarter.
"I was just trying to find some room to get him out, because he was travelling really well," Riddell said. "Luckily I got some room in the straight and he just flew home. I was pretty confident from that point because he was just going so well."
Verry Flash was bred by Don Goodwin, who shares ownership with the gelding's former trainer Nick Bishara. The son of Zed and the Danroad mare Opulence is a full-brother to the 11-time Group One winner Verry Elleegant.
Verry Flash has himself performed in black-type company, winning the Listed Rangitikei Gold Cup (1600m) in 2022 and placing in two editions of the Gr.3 Winter Cup (1600m). He has had a total of 71 starts for 14 wins, 18 placings and $373,284 in stakes.
In addition to his 11 wins on the flat, Verry Flash has also recorded three wins and two placings in a promising six-start hurdling career.