Ruggero won his dirt-course debut in an eventful running of Saturday’s $170,894 Cattleya Sho at Tokyo Racecourse, the first race of a three-race series that could produce a Japanese-based runner for the Kentucky Derby at Churchill Downs on May 5. Ruggero won the one-mile race by a half-length over Mic Ben Hur. Meiner Yukitsubaki, a colt by 2012 Kentucky Derby winner I’ll Have Another, finished third in the field of eight, a nose behind Mic Ben Hur. Ridden by Keita Tosaki, Ruggero stalked the pace before taking the lead in the final sixteenth from Morito Yubu, who led shortly after the start. A few strides after losing the lead, Morito Yubu collided with the inside rail in a manner that suggested the colt was trying to jump the rail. Jockey Hiroshi Kitamura was unseated, but did not appear to be bothered by the trailing runners. Ruggero is by the Australian-bred sire Kinshasha no Kiseki, a 15-year-old grandson of 1989 Kentucky Derby winner Sunday Silence. Ruggero, who is owned by Takashi Muraki and is trained by Yuichi Shikato, was purchased for approximately $343,904 as a weanling in 2015 and has won two of four starts. The colt was eighth in the Grade 3 Saudi Arabia Royal Cup on turf at Tokyo Racecourse on Oct. 7. The Japanese qualifying series for the Kentucky Derby was introduced last year, but there was not a Japanese-based runner in the Kentucky Derby in May. A similar series will begin in Europe this winter with one berth available to a horse that earns points in races in England, France, and Ireland. After Saturday’s Cattleya Sho, the series continues in Japan with the Zen Nippon Nisai Yushun at Kawasaki on Dec. 13 and the Hyacinth Stakes at Tokyo in February. The Cattleya Sho and Nisai Yushun are worth 10-4-2-1 points for the first four finishers, while the Hyacinth Stakes is worth 30-12-6-3. One invitation will be extended to a Japanese-based runner among the horses with the four highest point totals. There have been two Japanese-based runners in the Kentucky Derby, mostly recently Lani, who finished ninth in 2016. Lani, who won the 2015 Cattleya Sho before the Japanese qualifying series was launched, earned a berth in the Kentucky Derby by winning the United Arab Emirates Derby in Dubai in March 2016.