Naomi Osaka crashed out of the Canadian Open with a straight-sets defeat to Elise Mertens in the second round on Thursday.

The Belgian held her nerve for her second win over Osaka this year, beating her 6-3 6-4 in Toronto to set up a meeting with Liudmila Samsonova in the round of 16.

Osaka was caught out by making errors from the baseline and failed to gain any momentum as her preparation for the US Open took a hit with her early exit.

Despite the defeat, the former world number one remained upbeat about her performance as she looks to build on this result.

"I feel like I could have put a bit more on the court, a bit more from the baseline shots," Osaka said. "I got a bit caught up in the idea of being consistent and staying in the exchanges, I don't know.

"I'm happy with how I fought despite not winning, but I feel like I learned a lot.

"Unfortunately, I have always suffered a lot from my perfectionism, and I also tend to doubt myself a lot, but I think it's necessary to go through this process and have tough losses from which you can learn a lot about yourself.

"I know there will be many tough defeats like this one, but hopefully, I hope to be back in the top ten soon." 

Data Debrief: Fight fizzles out

Osaka struggled to gain a foothold in the match, losing her serve four times while only earning two breaks in return. 

She won just 37% of her second serve points (10/27) and failed to win more than two games in a row as Mertens edged out of her reach.