Sent out a red hot favourite for the 1400 metre assignment, she powered away for Blake Shinn to win by nearly three lengths in a dominant display.
"I've been lucky enough to ride some top class horses and she's right up there with the best I have ever ridden," Shinn said.
"She's amazing. A great filly."
Trainer John Thompson was also rapt with the ease of her win, but is taking it one step at a time when charting her autumn course.
"We go to the Coolmore next start," Thompson said. "That's always been the plan.
"Depending on how she goes there against the older mares we will then head to the Vinery or the Doncaster."
A $700,000 NZB Premier purchase from the Curraghmore Stud draft for Bart Cummings, First Seal runs for a powerful group of owners that includes China Horse Club, Raffles Thoroughbred Racing and Think Big Stud, which is managed by Duncan Ramage.
"Back in 2012 and 2013, I was commissioned by China Horse Club to source and buy some yearlings for them to be prepared by a variety of trainers," explained Duncan Ramage.
"We secured horses that went to Gai Waterhouse, Mark Kavanagh, Anthony Freedman, Robert Heathcote, Mike Moroney and Bart and James Cummings.
"First Seal was a horse that was identified as being suitable for Bart given his experience with her older sibling Book of Kells, so he was given the task of bidding on her at the sale."
Cummings secured the filly, with Coolmore left as the underbidder, but the budget set down by China Horse Club was exceeded.
"We were over budget and that forced me to 'phone a friend' as they say, which is how the partnership was formed with Dato Yap's Raffles Thoroughbreds, who bred the filly, agreeing to take a share and China Horse Club holding a majority interest," Ramage recalled.
"John Thompson had done some work in China for China Horse Club and the new partnership elected to send the filly to him and he's done a great job with her."
A Group I winner in the spring, First Seal has four wins and three seconds on the board from just eight starts with prizemoney of $625,060.
Bred by Raffles Dancers, First Seal is a three-quarter sister to Group II STC Tulloch Stakes winner Book of Kells and is the seventh winner for Episode, who won both the Group I SAJC Australasian Oaks and South Australian Oaks as well as finishing second in the Queensland Oaks.
Episode has a yearling full brother to First Seal that was sold at Karaka this year to Chris Waller Racing for $350,000.
Fastnet Rock has had some outstanding fillies over the years including the likes of Atlantic Jewel and Mosheen, with First Seal promising to put herself right up there with them.