Aidan O'Brien fields Happily in the Fillies' Mile at Newmarket as he hunts down a 24th top-level success of the year.

The trainer is on the cusp of breaking Bobby Frankel's record of 25 Group/Grade One victories in a calendar year and Happily will have the chance to add to her Moyglare and Prix Jean-Luc Lagardere wins as she spearheads a three-pronged O'Brien assault in Friday's race.

O'Brien also runs Magical and September, who finished second and third respectively in the Moyglare last month.

The trainer has won the past three editions of the Fillies' Mile with Together Forever, Minding and Rhododendron and says all three will run.

The trio leads the market with Happily the 6-4 favourite ahead of Magical (7-2) and September (6-1).

On Saturday, O'Brien is likely to have four runners in the Dewhurst Stakes at Newmarket to challenge the Sir Michael Stoute-trained odds-on favourite Expert Eye.Group One

The Irish trainer also has Johannes Vermeer and The Taj Mahal contesting the Group One Caulfield Stakes in Melbourne.