Charyn won his final race in Europe when prevailing in a thrilling finish to the Queen Elizabeth II Stakes.
The grey, trained by Roger Varian, travelled sweetly and found more under Silvestre de Sousa when challenged by the eventual second Facteur Cheval.
That left the winner with form figures for the season of 1121121, and he will race once more in Japan before being retired for a breeding career.
Kyprios claimed his seventh victory from seven races this season in the Long Distance Cup to continue his remarkable return from a life-threatening injury for champion trainer O’Brien.
The 8-11 favourite was put in a prominent position by jockey Ryan Moore and comfortably resisted the challenge of runner-up Sweet William.
Kyprios became the first Irish-trained horse to secure eight top-level Group One wins with victory in France just 14 days earlier, having missed much of last year with a serious leg injury.
“He’s a very special horse and something we’ve never seen before,” said O’Brien.
Conditions were testing after rain in the build-up meant the going became soft, heavy in places after two races.
As the sun broke out, a crowd of 29,000 saw the 10-1 chance Kind of Blue give James Doyle his first Group One winner for Watthan Racing, who retain him as jockey and recently bought the horse.
It was a third success in the Champion Sprint Stakes for trainer James Fanshawe after Deacon Blues (2011) and The Tin Man (2016).
Kalpana justified favouritism to run out a 100-30 winner of the Fillies and Mares Stakes for jockey James Doyle and trainer Andrew Balding in the Juddmonte colours while Carrytheone took the concluding Balmoral Handicap.
Oisin Murphy was crowned champion jockey for the fourth time, and the first since returning in early 2023 from a 14-month suspension for breaching Covid-19 rules and twice failing racecourse breath tests for alcohol.
Sean Dylan Bowen, who was riding at Catterick, claimed the champion apprentice jockey title after his battle with Joe Leavy went down to the final day.
Photo: Jason Moran / Eclipse Sportswire Jockey Mychel Sanchez will serve a seven-day suspension and pay an additional $1,750 in fines
Photo: Gulfstream Park / Lauren King Sovereignty, dramatic late-running winner of the Fountain of Youth (G2) March 1, is being pointed
Photo: Santa Anita / Benoit Photo Cavalieri and Alpha Bella, who finished one-two in the Grade 3 La Cañada in January at Santa Anita,
Photo: Gonzalo Anteliz Jr. / Eclipse Sportswire The stars will shine Saturday at Tampa Bay Downs, and not just in the Grade 3 Tampa Ba