Champion Irish trainer Aidan O'Brien now holds the new favourite for the Gr1 Lexus Melbourne Cup after Grosvenor Square's stunning 20-length victory in the Gr3 Irish St Leger trial, reports racenet.com.au. Facing only four rivals, Grosvenor Square (Galileo-Wadyhatta, by Cape Cross) dominated the race, gradually increasing his lead before securing a comfortable win, to put it mildly. Following Grosvenor Square's impressive display, TAB promoted him to $10 favourite in the Melbourne Cup betting market. O'Brien expressed his delight with the performance and indicated that the English St Leger at Doncaster on September 14 is the likely next target, rather than the Irish St Leger. "(Jockey) Ryan (Moore) said he was far from finished and he galloped right through the line. It's very hard not to go to Doncaster after that. He's so uncomplicated, you go out there and let him go. He handles soft ground as well," said O’Brien. If Grosvenor Square wins the English St Leger, it would likely result in a significant weight assignment for the Melbourne Cup, with weights being released three days after the race. Before heading to Australia, Grosvenor Square would need to complete a two-week quarantine period in Ireland followed by another fortnight at the Werribee quarantine facility south-west of Melbourne.