Sunday’s Irish St Leger at the Curragh offers a fascinating match-up between two standout stayers: Al Riffa, trained by Joseph O’Brien, and Illinois, from the powerful Aidan O’Brien yard.
Joint-favourites on most books, both boast top-level form, robust campaigns, and powerful ownership.
This year’s St Leger, the final Irish Classic of the season and a Group 1 over 1 mile and 6 furlongs, will not only determine the best stayer on the island but also shape tickets for international autumn targets like the Melbourne Cup.
Each horse brings unique strengths and questions, and their clash encapsulates the best of modern staying racing in Ireland.
Al Riffa – Joseph O’Brien
Al Riffa, a French-bred son of Wootton Bassett, is owned by the Al Riffa Syndicate after being acquired by Australian Bloodstock.
His career began with prominent early wins and a Group 1 success as a juvenile in the Vincent O’Brien National Stakes, setting a high bar for future progress.
Under Joseph O’Brien’s careful management, Al Riffa’s campaign has been a case study in patience and summer progression.
He kicked off 2025 with good placings in international contests, the Neom Turf Cup in Saudi Arabia (third) and the Prix Ganay at Longchamp (fourth), then found his best form stepping up in trip to 1m4f.
Notably, he was runner-up in the Hardwicke Stakes at Royal Ascot and peaked last time when winning the Group 2 Curragh Cup by a commanding five lengths.
That performance confirmed his stamina, cruising over the Irish St Leger distance, and underlined both class and staying power.
Joseph O’Brien, who twice won the Melbourne Cup as a trainer (the youngest trainer ever to win it at 24 years old in 2017), is targeting that race after the Leger, confident that Al Riffa’s versatility and late acceleration will suit international campaigns.
The Curragh is a favourite venue; he’s won three times and placed twice in five starts there.
His proven form at this track and trip, tactical flexibility, and consistent results make him a formidable contender.
Illinois – Aidan O’Brien
Illinois, by Galileo out of Danedrop, is owned by Coolmore partners Derrick Smith, Mrs John Magnier, and Michael Tabor.
He has been a model of consistency and progression. Last season, he captured the Queen’s Vase at Royal Ascot, showing clear-cut staying power at a mile and six furlongs.
The summer of 2024 and 2025 saw him run a series of high-class seconds: Grand Prix de Paris, Great Voltigeur at York, and a narrow defeat by Jan Brueghel in the St Leger at Doncaster.
His resilience was rewarded with an impressive win in the Group 3 Ormonde Stakes at Chester this May and solid runs in tougher assignments, including a near miss in the Ascot Gold Cup over 2½ miles.
Illinois is a horse who carries tactical speed and proven ability to dig in for a fight; his runner-up efforts are less a sign of vulnerability than proof of his will to battle in deep races.
The main question has been translating near-misses into top-level wins. However, his narrow defeats have generally come at the hands of subsequent Group 1 winners, and his final target last autumn, a decisive win in the Prix Chaudenay at Longchamp, showed his ability to produce a strong finish at the trip.
Family Connections
In terms of connections, the Joseph vs Aidan O’Brien rivalry is a major storyline for Irish racing fans.
Joseph O’Brien, the former champion jockey turned Classic-winning trainer, saddles both Al Riffa and outsider Leinster in the Irish St Leger.
Aidan O’Brien, his father and the most decorated Irish trainer of the past thirty years, fields Illinois and Queenstown.
Both are masters at preparing stayers for key autumn targets, and both have excellent records at the Curragh.
The contest is likely to be tactical, as each trainer has multiple runners who could be used to control pace or soften up the opposition.
Race Tactics
Recent form lines and conditions add layers to the analysis. Al Riffa produced his career-best run at the Curragh on good-to-yielding ground, a surface likely to be replicated on Sunday.
His ability to settle off a strong pace and then quicken in the last quarter mile offers plenty of tactical options for rider Dylan McMonagle.
Illinois, meanwhile, often races handily and has shown he can maintain a strong gallop when pressed. Christophe Soumillon’s booking signals Coolmore’s intention to maximise every tactical advantage, knowing the Belgian rider’s expertise in major staying contests.
Illinois’s past wins, including at Chester and Longchamp, were achieved by grinding down rivals in the final two furlongs.
His stamina is proven, though some analysts still query his killer instinct in a final battle.
Tactics could therefore be decisive. If the race unfolds at an even tempo, Illinois may try to strike for home early and outlast the chasers.
Al Riffa, with proven speed and the ability to accelerate away from rivals, might be asked to pounce late.
Neither horse is likely to be a front-runner, but with the field including speed from Amiloc and some longer-priced pacemakers, pace pressure could force both O’Brien-trained horses to show adaptability.
The Ultimate Duel
While Al Riffa and Illinois are close in the market and in ratings, what separates them on paper comes down to recent improvement and big-race temperament.
Al Riffa arrives off an authoritative win, is proven at the track, and is building towards a global campaign.
Illinois is consistent at the trip, has faced and almost beaten the best so far, and is due for a marquee win.
Both have pedigrees and training backgrounds suited for the Leger distance. Race conditions on Sunday should suit both, but the ability to accelerate in the last quarter mile, handle tactical changes, and draw on championship experience may decide which emerges as Ireland’s top stayer in 2025.
The duel between Al Riffa and Illinois, in the Irish St Leger, will be the centre piece of the Curragh’s autumn festival, drawing interest not only from Irish fans but also from punters and trainers targeting international staying prizes.
The outcome will shape narratives for the rest of the season and provide a new chapter in the O’Brien family rivalry – a moment where form, stamina, temperament, and tactics all converge over the classic staying distance.
BETFRED
