Canterbury Park’s popular Extreme Race Day returns Saturday with unusual horse races carded along with exhibition races for camels and zebras. Quarter Horses get things under way at 1:20 p.m. Central with the $20,000 Dash in a Flash, a 110-yard race that takes less than seven seconds to run. Thoroughbreds take the stage at 3:04 with the $22,000 Spurt in the Dirt, a $16,000 claiming race contested over two furlongs. The intriguing Battle of the Surfaces, consisting of simultaneously run route races on the main track and turf course, is scheduled to go at 3:35 p.m. The Grass is Greener, a $35,000 turf race restricted to runners who have never won a grass race, is the featured event, and the 7 1/2-furlong test came up tough. Among its nine entrants, classy competitors like top sprinter Picko’s Pride, Minnesota-bred star Bourbon County, multiple graded stakes winner Grand Contender, and Diamond Joe, a force in his native Nebraska, will line up at 4:45 p.m. Sponsored by the Minnesota Lottery, which offers a ticket giveaway to the first 10,000 adults through the gate, Extreme Race Day has a first post of 12:45 and reels in a large audience annually. However, the ostrich race has been grounded this season due to a regional outbreak of avian flu.