Olympic gold medallist and World Cup champion Marielle Thompson won a photo finish to take top honours at the Canadian ski cross championship Friday in Banff, Alta.

The 21-year-old from Whistler, B.C., beat out teammate Georgia Simmerling of West Vancouver, B.C., to cap off a notable season, which included gold at the Sochi Games and gold at the final World Cup race of the year to claim her second career Crystal Globe.

With Simmerling hot on her heels in the women's final, a late lunge for the line by Thompson gave her victory by the slimmest of margins.

"That was pretty exciting. I won by the length of a broken thumb," said Thompson, who tore a ligament in her thumb after crashing on a training run. "I guess you don't need thumbs for racing."

Tristan Tafel, of Canmore, Alta., took the men's race after taking the lead at the first turn to secure his second national title.