Australian John Millman is out of the Toronto Masters after retiring in the first round against American Jared Donaldson.

The 27-year-old lost the first set to Donaldson 6-4 before retiring at 4-3 in the second set, after just over an hour on court.

Millman joins fellow Australian Nick Kyrgios in being knocked out of the tournament after the 21-year-old’s shock loss to Canadian teenage wildcard Denis Shapovalov.

Bernard Tomic is the lone Australian heading into the second round after he defeated Alejandro Gonzalez in straight sets.

Tomic will play Canadian Steven Diez.

Meanwhile Frenchman Gael Monfils and Swiss second seed Stan Wawrinka are both through to the second round.