The County Tipperary handler has claimed the prestigious juvenile prize on a remarkable 16 occasions in the last 21 years, with Septimus (2005), St Nicholas Abbey (2009) and last year's hero Capri among those on the roll of honour for Ballydoyle.
The most famous recent winner of the Group Two is undoubtedly the brilliant Sea The Stars (2008), who was so masterfully trained by John Oxx.
O'Brien's Saxon Warrior, a son of Japanese superstar Deep Impact, made a huge impression on his racecourse debut at the Curragh and is bound to be popular with punters despite taking a marked step up in grade.
He is joined by stablemates Kew Gardens and Delano Roosevelt, who were second and third in a Group Three at Leopardstown a fortnight ago.
Mick Halford saddles the fourth from that race, Riyazan, and the select field is completed by the Brendan Duke-trained Warm The Voice.
The son of Vocalised, who carries the colours of Jim and Jackie Bolger, has won his last three starts and steps up to Pattern level for the first time.
The Beresford is supported by a trio of Group Three events, the first of which is the C.L. & M.F. Weld Park Stakes.
O'Brien is represented by Athena, Ballet Shoes and Sizzling, while Karl Burke's Ellthea and the Charlie Hills-trained Juliet Foxtrot are two formidable challengers from Britain.
Ball Girl (Ger Lyons), Fille Du Septembre (Dermot Weld), Mary Tudor (Willie McCreery) and New To Town (Jim Bolger) complete the line-up.
Just four runners are set to go to post for the Loughbrown Stakes over what will be a stamina-sapping two miles.
Willie Mullins and Pat Smullen team up with Renneti, while fellow leading National Hunt trainer Henry de Bromhead sends Stars Over The Sea into battle.
O'Brien's Wild Irish Rose and James Fanshawe's Return Ace are the other contenders.
The final Pattern race on offer is the Renaissance Stakes, which is headlined by Burke's Quiet Reflection.
The daughter of Showcasing struck Group One gold in the Commonwealth Cup at Royal Ascot and the Sprint Cup at Haydock last season, but has only been seen in competitive action once this term and finished down the field in Haydock's Temple Stakes back in May.
Her 10 rivals include Tom Hogan's stable stalwart Gordon Lord Byron, O'Brien's trio of Cougar Mountain, Peace Envoy and Alphabet, and Joe Murphy's hat-trick seeker Only Mine.