Milos Raonic has spoken out about the controversial net call made in his first-round match against Frances Tiafoe at the National Bank Canadian Open in Toronto.

Raonic strengthened his comeback to the sport at the ATP 1000 event, as the world No. 545 defeated world No. 10 Tiafoe in the opening round. The 2016 Wimbledon finalist won in a dramatic three sets, 6-7 (12), 7-6 (4), 6-3.

This comes as part of the Canadian's brief return to the sport after two years away. Raonic first came back during the grass court season but has suggested that he plans to retire after the upcoming US Open.

Despite his exciting win against a top-10-ranked player, Raonic was left a little confused by a decision made earlier in the match. While deep into a tiebreak at the end of the first set where his American opponent was leading 13-12, Raonic's shot hit the net cord which led Tiafoe to chase down a short ball.

After reaching the ball and hitting it back over to Raonic's side of the court, Tiafoe's momentum carried him right into the net, causing many to believe that the umpire would award the point to Raonic. This is because ATP rules state that if a player hits the net before the ball has bounced twice, the point goes to their opponent.

However, chair umpire Fergus Murphy decided to award the point to Tiafoe due to the fact that he had run into the section of the net outside of the singles net post. This meant that the 25-year-old claimed the first set.

Murphy went on to explain his decision:

"This section of the net doesn’t count as a touch. Only after the singles post [counts as a touch]," he said.

Despite this, Raonic was still baffled by the incident, leading to a lengthy debate in which he could be heard saying 'a net is a net'.

Nevertheless, the 32-year-old clawed back the points over the next two sets and went on to ultimately win the match. In his post-match interview, Raonic expressed his continued confusion at the call.

"I don’t want to say too much about it. I have to see if my beliefs are right. I have to check what it is because there’s a lot of things that don’t make sense. I understand the net might not be part of the net at that point. But if a ball was to hit the post & then come across as a let, I’m sure they’d play it as a let & not say the same thing.

"Maybe he made the right call. Maybe it was just the wrong way it was done by calling the score & then changing your mind, which kind of added to the whole drama of it. But I’ll take a look," he said.

Raonic will face Japanese player Taro Daniel tomorrow, August 9, in the second round of the Canadian Open.