Addeybb's impressive success in the £100,000 Wolferton Stakes was trainer William Haggas' ninth Royal Ascot victory, and his first in the 10-furlong Listed race on Tuesday.
The 5/1 chance, a five-year-old son of Pivotal, was eased down to beat 9/2 favourite Magic Wand (Aidan O'Brien/Ryan Moore) by two and a half lengths under Danny Tudhope.
Haggas said: "We thought Addeybb was in really good nick, the ground came right for him, and he has won well.I know it was only a Listed race, and he's a Group Two winner in a Listed race, but it was a strong field for the grade.
"He has just been really well these last two weeks and that combined with the cheekpieces and the ground - it all just came right for him today.
"He has won a Group Two on soft ground, but the most important thing for us is that he is back to himself and even better is that in his next race he will only have a Listed penalty. He will be going up to Group class now, but he does need this ground and I think he needs this trip too."
"His owner Sheikh Ahmed is a good supporter of mine and I'm delighted to win with this horse. We lost him a bit last year with the dry ground, but it was like it was written in the stars today."
Asked about Sea Of Class, who runs in tomorrow's G1 Prince of Wales's Stakes, he said: "I don't want to bottom her at this stage of the season. She's in great form and looks amazing. It's a fabulous race, but all the races she is going to run in are fabulous races. We just want to do right by her. I must stress, I'm keen to run, but I'm not keen to bottom her."
Tudhope was registering an 89/1 double on day one of the Royal Meeting following Lord Glitters' 14/1 victory in the G1 Queen Anne Stakes and a seventh victory overall at Royal Ascot.
He said: "I was very lucky to get on Addeybb at the right time.
"He loves soft ground and he was in a different league in this grade.
"These sort of conditions really suit and I was delighted when the rain came.
"I was travelling so well and had so much horse under me - it was just a matter of when to push the button - I'm very grateful to be on board.
"I've had a few winners for William Haggas this year and I was very grateful to get the ride on him. I work hard and every day is a tough day.
"You have your ups and downs, but these sort of days make it worthwhile."
Magic Wand, trained by Aidan O'Brien, and sent off the 9/2 favourite, came home two and a half lengths second to Addeybb (5/1) in the final race of day one at Royal Ascot, the Listed Wolferton Stakes over a mile and two furlongs.
O'Brien commented: "I am delighted, she ran a great race. She prefers better ground, but I am delighted by her run.
"I think she could go to Belmont or somewhere like that next."
Jockey Ryan Moore added: "She ran a super race - I would say the ground just blunted her speed."
Mark Johnston trained the third home, 5/1 chance Elarqam, who was beaten a nose by the runner-up. Johnston said: "The ground is soft and he has clearly handled it perfectly well, but has run out of petrol coming to the line.
"I said turning for home the danger is behind, and Ryan [Moore, on Magic Wand] was stalking us.
"We have no complaints, I think the horse is in great form and has run a great race - these conditions have just found him out.
"It has taken us a while to decide between a mile and a quarter or a mile, and this tells us that a mile and a quarter is the limit of where he can go. A mile and a quarter on good ground would be his ideal."
5.35pm Wolferton Stakes (Listed), 10f
1 Addeybb (Sheikh Ahmed Al Maktoum) William Haggas 5-9-03 Daniel Tudhope 5/1
2 Magic Wand (Michael Tabor, Derrick Smith & Sue Magnier) Aidan O'Brien IRE 9/2 fav
3 Elarqam (Hamdan Al Maktoum) Mark Johnston 4-9-06 Jim Crowley 5/1
Time: 2m 6.90s
Distances: 2½, nse
Tote Win: £6.00 Places: £2.05, £1.95, £2.10 Exacta: £31.60
Breeding: ch g Pivotal (GB) - Bush Cat (USA) (Kingmambo (USA))
Breeder: Rabbah Bloodstock Limited
William Haggas - 9th Royal Ascot winner
Daniel Tudhope - 4th Royal Ascot winner