Tokyo,  Taylor Fritz moved into the semifinals of the Japan Open Tennis Championships on Friday following the withdrawal of Nick Kyrgios due to a left knee issue.

The pair had been due to meet in the night session at the ATP 500 event, where Kyrgios lifted the trophy in 2016.

"It's obviously very disappointing. It's one of my favourite tournaments. I've had great memories here... It's heartbreaking, but I'll be here next year. That's for sure," Kyrgios said in a press conference.

The Tokyo fifth seed also pulled out of Atlanta earlier this year with a left-knee issue before rebounding in time to reach the US Open quarter-finals.

"I've been playing amazing tennis all year and actually was dealing with a bit of a knee issue around the US Open time. I got back home and probably didn't take enough time off, to be honest. I went straight back into training," he said.

The 2016 Tokyo champion had been in fine form this week with singles wins against Chun-Hsin Tseng and Kamil Majchrzak in addition to a run to the doubles semi-finals alongside Thanasi Kokkinakis. The Australian pair has also withdrawn from the doubles draw as a result of Kyrgios' injury.

"The Japanese fans are some of my favourites to play in front of. It's been such an amazing week. Obviously playing four matches and winning all four, I've been feeling great. I definitely felt like I was a threat to win the tournament and go all the way in singles and doubles," Kyrgios said.

Kyrgios plans to return to the ATP Tour later this month in Basel and Paris.

Meanwhile, the third seed Fritz had not won a match in three previous appearances in Tokyo but has battled hard to advance through the draw this week in the Japanese capital.

The American saw off both James Duckworth and Hiroki Moriya in three sets to set the quarter-final clash with Kyrgios. Those victories came off the back of the American spending a week in full quarantine due to testing positive for Covid-19 in Seoul last week.

Fritz's opponent in his first ATP 500 semi-final of the season will be seventh seed Denis Shapovalov, who defeated ninth seed Borna Coric 6-4, 6-3. Shapovalov owns a 4-1 ATP Head to Head record against him.

Shapovalov converted on three of his four break chances to earn his first ATP Head to Head win against Coric in his third try. The seventh seed dropped serve on the only break point he faced as he failed to serve out the opening set at 5-4, but he snapped back to secure the set on return.

After breaking again midway through the second set, he rode strong serving to victory in one hour, 17 minutes. The 23-year-old lost just three points on his own delivery in the second set, during which he enjoyed a run of 13 straight points won on serve.