The anticipation is palpable at the Curragh as the 2025 Irish St Leger shapes up to be one of the most compelling Group 1 contests of the season. Scheduled for Sunday, September 14, at 4:25 PM, this year's renewal is more than just the final Irish Classic—it's a clash of generations, trainers, and equine stars, all converging over one mile and six furlongs for a prize that will resonate far beyond Irish shores.
Headlining the field are two powerhouses: Al Riffa, trained by Joseph O'Brien, and Illinois, representing the formidable Aidan O'Brien stable. Both horses arrive at the Curragh boasting top-level form, robust campaigns, and a shared hunger for Group 1 glory. But with a field of nine declared, including the unbeaten three-year-old Amiloc and a supporting cast of proven stayers, the stage is set for a tactical and thrilling battle.
Al Riffa enters the fray as one of the joint-favourites. This French-bred son of Wootton Bassett, now owned by the Al Riffa Syndicate following his acquisition by Australian Bloodstock, has taken his owners on a remarkable journey. His juvenile season was capped by a Group 1 triumph in the Vincent O'Brien National Stakes, laying the foundation for a campaign built on patience and steady progression. Under Joseph O'Brien's watchful eye, Al Riffa has tackled international assignments with distinction in 2025, finishing third in the Neom Turf Cup in Saudi Arabia and fourth in the prestigious Prix Ganay at Longchamp.
It was a return to home soil that saw Al Riffa truly hit his stride. He was a close second to Rebel's Romance in the Hardwicke Stakes at Royal Ascot, but it was his emphatic five-length victory in the Group 2 Curragh Cup over this very course and distance in July that stamped him as the horse to beat. That win not only showcased his stamina but also his ability to quicken away from rivals in the closing stages—a trait that could prove decisive on Sunday. Al Riffa's Curragh record is exemplary, with three wins and two placings from five starts, and his tactical versatility gives jockey Dylan McMonagle plenty of options when the stalls open.
"Al Riffa’s campaign has been a case study in patience and summer progression," notes one analyst, and it's hard to argue. Joseph O'Brien, already a two-time Melbourne Cup-winning trainer and the youngest ever to claim that honor at just 24 in 2017, has made no secret of his ambitions to take Al Riffa to Australia after the Leger. "We know he stays, he travels, and he has the turn of foot for these big autumn targets," O'Brien has said. The Irish St Leger, then, is both a goal in itself and a stepping stone on a global journey.
Standing in his way is Illinois, the pride of the Coolmore partners Derrick Smith, Mrs John Magnier, and Michael Tabor. Trained by Aidan O'Brien, Illinois has been the very model of consistency and class. His three-year-old campaign saw him land the Queen's Vase at Royal Ascot, confirming his staying credentials. Since then, he has been a fixture in the top echelons of European staying races, finishing runner-up in the Grand Prix de Paris, the Great Voltigeur at York, and suffering a narrow defeat in the St Leger at Doncaster.
Illinois kicked off 2025 with victory in the Group 3 Ormonde Stakes at Chester and has since added a pair of high-profile second-place finishes to his résumé: the Gold Cup at Royal Ascot (over 2½ miles) and the Goodwood Cup. Now, with first-time cheekpieces applied and Christophe Soumillon booked for the ride, Illinois looks primed to finally convert his string of near-misses into a marquee Group 1 success. "The likeable Illinois can respond well to first-time cheekpieces and end his frustrating run of Group 1 seconds," according to Timeform’s preview, and many punters agree that he’s due a change in fortune.
What makes this year’s Leger so intriguing is the O’Brien family rivalry at its heart. Joseph O'Brien, the former champion jockey turned Classic-winning trainer, not only saddles Al Riffa but also Leinster, who won the Irish St Leger Trial at the Curragh just 29 days ago by an impressive 4¼ lengths from Dallas Star. Aidan O'Brien, meanwhile, fields both Illinois and Queenstown, another runner who returns after a strong handicap performance in the Ebor at York. The tactical battle between father and son is a subplot that adds even more spice to an already flavorful contest.
The supporting cast is far from mere window dressing. Amiloc, trained by Ralph Beckett and ridden by Rossa Ryan, stretches his unbeaten record to five after a gritty win in the Group 2 King Edward at Royal Ascot back in June. As a three-year-old, he carries less weight than his older rivals and has been given time to mature since his last start. If he stays the trip, he could well shake up his more established opponents. Crystal Black, Dallas Star, Al Qareem, Leinster, Queenstown, and Waldadler round out a field where every runner brings a story and a shot at Classic glory.
Pace and tactics could prove decisive. With speed likely to come from Amiloc and the possibility of Ballydoyle deploying Queenstown as a pacemaker, both Al Riffa and Illinois will need to show adaptability. Soumillon’s experience in major staying contests could be a trump card for Illinois, especially if he tries to strike for home early and test his rivals’ stamina. Al Riffa, with his proven finishing kick, may look to pounce late, using his acceleration to maximum effect in the final furlong.
As for the ground, current forecasts suggest conditions similar to those that saw Al Riffa produce his best at the Curragh—good to yielding. That should suit most of the field, though the proven track form of both Al Riffa and Illinois gives them a slight edge in the eyes of many observers.
Beyond the headlines, the 2025 Irish St Leger is a race that will shape the international autumn calendar. The winner will almost certainly book a ticket to the Melbourne Cup, while the form lines established here will inform campaigns across Europe and beyond. The duel between Al Riffa and Illinois encapsulates not just the best of Irish staying racing, but also the evolution of the sport: global ambitions, family rivalries, and horses bred and trained to excel at the highest level.
With the field assembled and excitement building, all eyes turn to the Curragh for what promises to be a classic in every sense. Whether it’s Al Riffa’s surge, Illinois’s resilience, or a new star emerging from the pack, Sunday’s Irish St Leger is set to deliver a spectacle worthy of its storied history.
As the runners head to post, the sense of anticipation is unmistakable. The outcome remains undecided, but one thing’s for sure: whoever prevails will have earned their place in the annals of Irish racing and set the tone for the rest of the international season.
