An already stiff Japanese challenge for the Dubai World Cup programme at Meydan on March 30 was further fortified on Wednesday when it was announced that the Mikio Matsunaga-trained duo of Matenro Sky (Jpn) (Maurice {Jpn}), upset winner of the G2 Nakayama Kinen, and the three-year-old colt Ballon d'Or (Jpn) (New Year's Day) have accepted invitations to the G1 Dubai Turf and G2 UAE Derby, respectively. Netkeiba was first to report the news. The five-year-old Matenro Sky broke through at the stakes level in the Listed Rigel S. going a...