Félix Auger-Aliassime’s National Bank Open is over before it even started.

In a major blow to the tournament, the top-ranked Canadian withdrew from his hometown event some two hours before his opening match Wednesday at IGA Stadium after sustaining a back injury during practice.

Auger-Aliassime, ranked fourth in the world, entered the ATP Masters 1000 event as one of the favourites. His No. 2 seed was the highest ever for a Canadian at the tournament in the Open Era.

The 25-year-old from Montreal was set to face French qualifier Titouan Droguet in the second round as he opened his bid to become the first Canadian man to win the singles title since Robert Bédard in 1958.

Auger-Aliassime was also the last Canadian standing in the men’s singles draw after Denis Shapovalov and Gabriel Diallo retired with injuries Tuesday.