Aidan O'Brien and Johnny Murtagh bagged their fourth Group One of the week as Yeats stole the show on day three of the Royal meeting at Ascot.
Ballydoyle's brilliant stayer showed his tenacity to record a third successive win in the Gold Cup, matching the achievements of Sagaro, who won the race between 1975 and 1977.
Geordieland grabbed the lead with two furlongs to run but Yeats fought back to slam Jamie Osborne's grey by five lengths, with Coastal Path wilting into third.
"It's unbelievable and I didn't really think it would happen," beamed an elated O'Brien after Yeats had justified favouritism.
"It's down to a lot of hard work from a lot of people and Johnny gave him a wonderful ride."
"He got him into a great rhythm before letting him go and his timing was perfect."
Murtagh said: "He stays the trip well, he has the heart of a lion and I knew that."
"He has big lungs and I knew that if we got there at the four-marker it would take something special to beat him."
John Gosden and Jimmy Fortune had gone close with Raven's Pass behind Henrythenavigator on Tuesday and they combined to hit the target with Michita in the Ribblesdale Stakes.
Riding for the same connections, Stonerside Stable, Fortune enjoyed a smooth passage and always had matters in hand as Michita flew home to slam Arthur's Girl by three and a half lengths.
Lightning struck twice for Howard Johnson, Robert Winston and Graham Wylie as they secured the Norfolk Stakes with favourite South Central - three years after Masta Plasta bagged the five-furlong event for the same team.
Fifteen Love claimed a win in the Britannia Stakes for Roger Charlton and Steve Drowne, while Kerrin McEvoy produced William Haggas' Collection fast and late to bag the Hampton Court.
The concluding King George V Handicap went to Sir Michael Stoute's Colony, who came home best of all to give Ryan Moore his first ever Royal Ascot winner.