Sunday promises a packed schedule of top‑flight racing across three venues – Brighton, Worcester and the historic French track at Deauville – all streamed live on Sky Sports Racing. The day’s marquee attraction is undoubtedly Diamond Necklace, the three‑year‑old filly trained by Aidan O'Brien, who will front a glittering field in the Group One Summe Prix Jean et Louis Romanet. Diamond Necklace has been the dominant force in her generation, having won every one of her six career starts, four of them at the highest Group One level.

After a decisive victory in the Nassau Stakes at Goodwood last month, she returns to face older horses once more and is poised to extend her unbeaten run to seven consecutive wins. Her blend of speed, stamina and tactical versatility makes her the clear favorite, but the race will still be a test of class against a strong international contingent.

Joseph O'Brien’s filly Rebel Moon also merits serious attention. Ridden by Dylan Browne‑McMonagle, she impressed when she finished fourth in the Irish Oaks and could easily improve on that effort. The filly possesses a lively turn of foot and, with the distance of the Summe Prix suiting her pedigree, she could be the first to challenge Diamond Necklace’s supremacy. Another contender of note is Aventure, the 2022 Prix Vermeille champion who will be guided by Christophe Ferland.

Although she appeared a touch off‑colour in her recent run behind Calandagan at Saint‑Cloud, her Group Two triumph in May suggests she still has plenty of quality left. If she can rediscover her best form, she may well be the most dangerous opponent for the O’Brien stable. Among the remaining runners, Red Letter is rated the best of the rest, offering solid form and a respectable record at the Group level. While she may not be the outright favorite, she will be looking to exploit any weakness shown by the leading fillies.

The Summe Prix Morny, a stunning renewal of a classic sprint, features eight sprinters, including Orthodox and Man’s Best Friend. Aidan O'Brien has entered three horses in the contest, with Man’s Best Friend being the pick of Ryan Moore. The colt showed promise when he finished fourth on debut, then secured a maiden at Naas before taking the Group Two Richmond Stakes at Goodwood. That progression signals a bright future, and the Morny will be a key stepping stone toward higher‑level sprinting contests.

Great Barrier Reef, a former Coventry Stakes winner at Royal Ascot, has encountered a recent setback and will be closely watched by punters. If he can return to his previous best, he could be a real factor in the sprint division. Orthodox, the Norfolk Stakes champion, is another intriguing prospect for trainer Clive Cox. The colt dominated over five furlongs and should take the step up to six without difficulty, making him a strong candidate for the top spot in the Morny.

Senorita Bonita, who out‑performed Libertango at Newmarket in her most recent outing, adds depth to the field. With Libertango scoring a win at York this week, Senorita Bonita’s form suggests she could be a serious threat if she continues her upward trajectory. Turning to the Brighton Summer Series Final, the Blackmore Equestrian Construction Handicap will take place at 3:50 pm, promising a fiercely competitive showdown. Arnaz, representing Mark Loughnane and ridden by his son Billy, arrives in high spirits after a double victory at Chepstow and should be a contender in the warmer conditions.

Several other horses, including recent winners Diomed Spirit and Big Time Rascal, also have each‑way chances, while top‑weight Prefer The Sister commands respect after leading the field in her last five starts. The day’s program also includes several notable Group Two contests at Deauville.

At 12:58, the Prix du Calvados will see Dee’s Funny Girl, trained by Donnacha O’Brien, take to the course. Earlier, at 1:33, the Prix Kergorlay will feature the popular Santorini Star, with Defiantly representing Joseph O’Brien. Meanwhile, back in England, the Brighton Class Four race will be led by Sea Suite, who tops a competitive field.

For racing enthusiasts, Sky Sports Racing offers a comprehensive suite of news, interviews and feature pieces that can be accessed on mobile devices, ensuring fans never miss a story. Whether you are tracking the progress of Diamond Necklace’s unbeaten streak, evaluating the sprint prospects in the Summe Prix Morny, or following the action in the Brighton summer series, the channel provides live coverage, expert analysis and up‑to‑date form guides. In summary, Sunday’s racing card is a showcase of elite talent across distances and ages.

Diamond Necklace stands out as the headline act, but the depth of quality in the fields – from the seasoned Aventure to the rising stars Orthodox and Man’s Best Friend – guarantees an exciting day of high‑stakes competition. Tune in to Sky Sports Racing for live streams, in‑depth commentary and all the latest updates from the world of thoroughbred racing.