09/13/2007 12:00AM

O'Brien sends out four to challenge Lucarno

EmailLucarno faces a phalanx of Aidan O'Brien-trained challengers at Doncaster on Saturday when he will try to give American owner George Strawbridge his first British classic triumph in the St. Leger Stakes. The 1 3/4-mile, 132-yard Group 1 race is worth $1omillion for the first time this year in its 232nd running.

Trainer John Gosden has expressed doubts about the ability of his Dynaformer colt to stay the St. Leger distance, but Lucarno's victory in the 1 1/2-mile, Group 2 Great Voltigeur Stakes at York last month came at the expense of three of his St. Leger rivals, all of them trained by O'Brien: Macarthur, Acapulco, and Mahler. Jimmy Fortune will take his usual place aboard Lucarno, who led virtually throughout when beating Macarthur 1 1/2 lengths into third in the Great Voltigeur.

A full brother to 2005 Epsom Derby winner Motivator, Macarthur has failed to live up to his promise, but O'Brien also has the 9-4 favorite Honolulu, who may be sitting on a big effort. A half-length second against older horses in the 1 3/4-mile Ebor Handicap at York, Macarthur will have Johnny Murtagh aboard.

Fifth in the Great Voltigeur, Mahler has won the two-mile, Group 3 Queen's Vase at Royal Ascot and will be ridden by Michael Kinane. Acapulco, fourth in the Great Voltigeur, could be sacrificed as a pacesetter for his three O'Brien stablemates.

Gosden will also saddle Raincoat, but the Barathea colt failed as the favorite in the French Derby and was only third behind Man o' War flop Yellowstone in the Group 3 Gordon Stakes. Michael Stoute has supplemented his two-time handicap winner Regal Flush in search of his first St. Leger victory, but the value play at 11-1 looks like Veracity, a Michael Jarvis-trained son of Lomitas who was second last time in the two-mile Goodwood Cup against older horses.

Yeats tries Irish St. Leger again

It will be difficult to deny O'Brien in the Group 1, $414,000 Irish St. Leger at the Curragh, where Yeats will use the 1 3/4-mile race as a prep for the Melbourne Cup.

O'Brien is hoping that Yeats will be third-time lucky, as the Sadler's Wells 6-year-old was fourth in this race two years ago and second last year. He has been freshened since his second win in the Ascot Gold Cup on June 21 but could be vulnerable to stablemate Scorpion, the winner of the Doncaster St. Leger two years ago and the 1 1/2-mile, Group 1 Coronation Stakes in June. Group 3 winner Mores Wells, the only 3-year-old in the field, and Bellamy Cay, gelded since joining Dermot Weld this spring, appear to be in the race for third.