Grand Prix Boss came with a late rush to win Japan’s premier juvenile contest, the $1.6 million Asahi Hai Futurity Stakes at Nakayama on Sunday, as he ran down a pair highly regarded colts from the first crop of Deep Impact. Seemingly beaten at the head of the stretch in the Grade 1 mile, the 13.60-1 Grand Prix Boss was angled out by his Italian rider Mirco Demuro, forcing Christophe Soumillon to check aboard the 4-5 favorite, Sadamu Patek. By the sprinting stallion Sakura Bashin O, the Yoshito Yahagi-trained Grand Prix Boss rallied wide to lead in the final strides, defeating the 9.30-1 Real Impact and his Irish rider Fran Berry by three-quarters of a length, with the 5.20-1 Libertas third, a head farther back. The unlucky Sadamu Patek, who had broken slowly in addition to being impeded in the stretch, was along for fourth, a neck behind Libertas. Grand Prix Boss had to sweat out a stewards’ inquiry, but the judges decided to allow the order of finish to remain unchanged. The time for the right-handed mile on firm ground was 1:33.90. Now 3 for 4, Grand Prix Boss had previously won the seven-furlong, Grade 3 Keio Hai Nisei Stakes. He is very likely to be named the champion Japanese 2-year-old colt as a result of his Futurity victory, but the best juvenile in Japan is probably the Reve d’Essor, the winner last week of the Grade 1 Hanshin Juvenile Fillies who had beaten Grand Prix Boss into seventh place when winning the Grade 2 Daily Hai Nisei Stakes on Oct. 16 at Kyoto where she was the only female in the 12-runner field.