Dettori, fresh from landing the Gold Cup 24 hours earlier, guided Porta Fortuna to victory in the opening Group Three Albany Stakes for Donnacha O'Brien.
"80 at Ascot - I achieved my dream," he said. "I love this place so much. It is unbelievable."
The 52-year-old, who made it 81 on Coppice later in the Sandringham Stakes, retires at the end of the season and said he had no idea about what he might be doing come next year's Royal Ascot.
"I am only thinking about the next race, enjoying the moment."
For 24-year-old O'Brien it was his first Royal Ascot winner - his father Aidan O'Brien, who saddled the second home, has over 80.
"Wonderful to have a winner at Royal Ascot," said O'Brien junior.
"I am delighted that I can experience what my father has enjoyed so many times."
Despite coming off second best his father took pleasure in his son's success.
"So delighted for Donnacha, he works really hard so due reward for that."
Dettori did not have a ride in the Group One Coronation Stakes won by Weld's odds-on favourite Tahiyra.
'Worthy winner'
This was Weld's second success in the fillies' mile feature - 45 years after his first, in 1978, nine years before winning jockey Chris Hayes was even born.
The Irish 1,000 Guineas winner Tahiyra made a slow getaway and then veered across the path of eventual second Remarquee, prompting a stewards inquiry.
Despite a lengthy wait for the outcome Tahiyra, owned by the Aga Khan, justifiably kept the race.
"She was a worthy winner," said Weld, 74.
"It was a technical, tactical race with a small field, it was a lovely ride from Chris."
The jockey said Tahiyra had been "a little agitated coming out of the stalls and slipped".
"I had to get her to relax off a slow pace" he added.
Earlier, Shaquille gave trainer Julie Camacho her first winner at Royal Ascot - also their first Group One - with Aidan O'Brien's odds on favourite Little Big Bear making do with second in the Commonwealth Cup.
"I was very nervous, I watched it on my own," said Camacho.
"This is massive. I never thought I would train a Group One winner at Royal Ascot."
Shaquille's victory was remarkable as he had jumped up in the stalls as the horses broke for the race losing yards on his rivals.
However, Oisin Murphy kept his nerve and produced him with an impressive burst of speed to give him his first win this week and 11th at Royal Ascot.
"The race was almost over but you just have to take a deep breath and hope they have gone too fast and slow down at the end," said Murphy.
Murphy - seen as the successor to Dettori both on the track and as an ambassador off it - has enjoyed a successful season after returning from a long ban for breaches of Covid regulations and for being over the alcohol limit on two occasions when he turned up to ride.
"I had a fantastic comeback," he said.
"I have had three seconds before today, it is brilliant to get off the mark now."
Aidan O'Brien's other son Joseph also got on the scorecard.
His Okita Soushi won the Duke of Edinburgh Stakes with Dettori's great rival Ryan Moore registering his fifth win of the week and his 78th at Royal Ascot.
"Amazing family Aidan sets the standards but the two boys are doing tremendous," said Moore.
Aidan went over and shook hands with Joseph, who breathed more a sigh of relief than anything else at breaking his drought for the week.
"It has been a frustrating week as we have hit the crossbar several times," said 30-year-old Joseph.
Later Auguste Rodin, Aidan O'Brien's Epsom Derby winner, was paid a sizeable compliment when Derby runner-up King Of Steel made short work of a class field in the King Edward VII Stakes.
