Yeats secured his place in the history books as he became only the second horse to complete a hat-trick of wins in the Gold Cup at Royal Ascot.
Sagaro won three successive renewals between 1975 and 1977 and the Aidan O’Brien-trained Yeats equalled that record with victory in the hands of Johnny Murtagh.
Sent off the 11-8 favourite, Yeats beat Geordieland with Coastal Path back in third.
Murtagh initially sat a little off the early pace, which was set by Le Miracle, before sending Yeats to the front with around half a mile to run.
Stephane Pasquier, alive to the threat, soon sent Coastal Path in pursuit and that pair briefly looked to be going the better as they swung for home.
The race many had wanted to see was developing beautifully at this point, as Jamie Osborne’s Geordieland also swung in travelling strongly in third.
He actually took over soon after the principals turned in and appeared to find for pressure until Yeats dug deep to regain the initiative.
Having got back in front there was no stopping O’Brien’s star stayer and he powered on to defeat a leg-weary Geordieland by five lengths, with Coastal Path a further four and a half lengths away.
An elated O'Brien said: "It's unbelievable and I didn't really think it would happen.
“The lads (at home) did a great job to get him here for one Gold Cup and then he came back for a second one and now a third one – it’s unbelievable.
“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.”
O'Brien added: "He's a very straightforward, clean-winded and very sound horse and the lads say he gets very aggressive when he's fit.
“He’s a great mover with massive lungs and he has a massive heart.”
Asked about the possibility of a record-breaking four triumph next year, O’Brien said: “I don’t know when the time will come to preserve his genes and that is the reality as we’ve never had a horse with as big a pair of lungs and as big a heart as he has – they are physical things.
“This is very special for everybody involved. I am very privileged to have these special horses to train.”
Murtagh added: “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.
“He’s just got that extra bit of class to come back here and win a third Gold Cup. I’m just delighted to be involved with the team.”