Poet's Word has won the £1.25m King George VI and Queen Elizabeth Stakes at Royal Ascot - handing trainer Sir Michael Stoute a record sixth success.
Jockey James Doyle took the 7/4 chance past stablemate and 6/4 favourite Crystal Ocean - ridden by William Buick - inside the final half-furlong, winning by a neck in an epic finish.
Coronet finished third under Olivier Peslier for trainer John Gosden.
It comes 37 years after Sir Michael's first King George win with Shergar.
Since then, Sir Michael has trained Opera House (1993), Golan (2002), Conduit (2009) and Harbinger (2010) to victory in the mile-and-a-half-long feature.
Victory for Poet's Word means Sir Michael has moved ahead of fellow trainers Dick Hern and Saeed bin Suroor with his sixth King George win.
The trainer paid tribute to this year's winner and runner-up. "Two wonderful brave athletes. The first reaction is you feel sorry for the one that got beaten," he said. "It's taken a long time [to get the sixth victory]."
'He's a star'
The triumph came five weeks after Doyle rode Poet's Word to victory in the Prince of Wales' Stakes over 10 furlongs at Ascot.
Doyle said: "He's a star, there were questions over his best trip, what's his best trip now? Winning the King George over a mile and a half - he's so versatile.
"I ended up following Coronet, which wasn't really the plan. I wanted to be in front of her and if I had have been I think I would have won a bit easier.
"I left him a bit of a task, they went quick and I didn't want to start chasing a position."
BBC horse racing correspondent Cornelius Lysaght
Poet's Word may not necessarily be a household name in the mould of past winners like Mill Reef, Shergar or Dancing Brave, but he has risen to the top this year most assuredly.
The thrilling finish that he and James Doyle served up as they kept on from behind, bearing down relentlessly on Crystal Ocean, was in the great tradition of King Georges over the decades.
The nine lengths gap to the third says it all. Record-breaking Sir Michael Stoute, continuing a fine summer at Ascot, summed it up to perfection: after a race like that, he said, there didn't deserve to be a loser.