Third seed Felix Auger-Aliassime has been knocked out by Russian Karen Khachanov in the second round of the US Open.

A two-time finalist at the tournament, the Canadian was beaten 6-7 (5-7) 6-3 6-2 6-2 by the unseeded Russian.

Auger-Aliassime managed to fend off his opponent to edge the first set in the tie-break.

However, a mixture of too many unforced errors, coupled with some brilliant winners down the line from Khachanov, sent the 26-year-old crashing out.

His exit followed that of 24-time Grand Slam champion and fourth seed Novak Djokovic in the first round.

Auger-Aliassime reached the quarter-finals of this year’s Wimbledon and French Open, but withdrew from the Rogers Cup in Montreal in August with a back injury.

“Maybe he had some physical issues,” said Khachanov, 30. “It’s part of our sport, it’s part of tennis.

“I’m super happy to get this win.”