At the start of the 2006 season, Grain returned to her professional cycling career when she signed an exclusive contract with Hong Kong's Giant Pro Cycling. She capped a successful season by taking home the silver medal in the women's elite 8 km scratch race at the UCI World Championships in Bordeaux, France, and mounted top-four finishes in both road and points race at the Commonwealth Games in Melbourne, Australia, moving her up to top ten places in the UCI world rankings. Reaching the peak of her sporting career, Grain burst again into the road cycling scene by defending her Tour de Gastown title on that same year, the first being done in 2005.