Jackson, of Landsdale, won the men’s under-17 60km road race on what was a testing course for all competitors, including several climbs and a 1km dirt section, finishing in 1:35.19 ahead of 80 competitors.
Despite a crash midway, Jefferies, of Marangaroo, won the women’s under-17 30-minutes plus three laps criterium race.
She was allowed a lap out by the officials and, after an amazing ride, she managed to find her way to the front of the pack on the final lap and sprint to victory.
Jackson also competed in the men’s criterium, coming second.
Fellow PuraVida Apollo Racing Team member Shannon Sherwin, of Padbury, also brought home a bronze medal in the women’s under-17 40km road race.