All eyes before the six-furlong contest were on the winner's stablemate and last year's highest-priced yearling in Europe, 3.6million guineas purchase Noble Dynasty.
However, the 5-2 favourite was upstaged by his lesser-fancied stablemate with the son of Sharmadal prevailing by a neck.
Appleby said of the 4-1 winner: "I'm pleased with the winner and a step up in trip will see further improvement. Something like the Chesham will hopefully fall into his category and he qualifies being by Shamardal.
"The second horse I was delighted with him. You could see there he was raw and rolling around. Once the penny dropped he put in some nice late headway.
"He is not an Ascot horse. We will not push him too much at this stage. We will step him up to seven for a maiden, then look at some nice summer targets."
Dashing Willoughby ended a losing run stretching back to last year's Queen's Vase at Royal Ascot with a front-running success in the Betfair Exchange Buckhounds Stakes.
Having teamed up to land the Qipco 2000 Guineas with Kameko on Saturday, trainer Andrew Balding and jockey Oisin Murphy struck again in the mile-and-a-half Listed prize.
Maintaining a good gallop from the outset, the 17-2 shot continued to find plenty from the front to deny the hat-trick-seeking Secret Advisor by a length.
Balding said: "He was a Group Two winner last year and he ran very well at the July Course in the Princess of Wales's. He was entitled to go well enough today.
"I thought the ground might be a little bit quick, but they did have a little bit of rain. He is fairly versatile, but I did think it would be too fast for him to win. He did a lovely job, Oisin.
"The only race for him is the Gold Cup, but there is the Hardwicke. I will talk to the owners and see what they want to do. It is nice to start the year like that
The Kingsclere handler issued a positive update on Kameko following his Classic success at the track 24 hours earlier.
He said: "He was reported sound this morning. He lost eight kilos, but he ate up over night and he looked fine and well this morning."
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