Tokyo,  The fourth-seeded American Frances Tiafoe raced to the semifinals of Japan Open Tennis Championships with an impressive 6-0, 6-4 victory against Miomir Kecmanovic, here on Friday.

"I was really solid from the start. I was moving really well, I hit the ball well from the back of the court. I made it really tough for Miomir today. He played some great tennis. I was lucky enough to get it done in straight sets. Performances like this are big," Tiafoe said in his post-match press conference.

In just more than 30 minutes, Tiafoe won the first eight games of the match to take command under the closed roof in the Ariake Colosseum. After getting on the board for 1-2 in the second set, Kecmanovic called for the physiotherapist and had his lower back worked on. He created a 15/40 opening with Tiafoe serving at 3-2, but could not convert as the American began a run of eight straight points on serve.

Stepping up to the line at 30/30 as he served out the match, Tiafoe overcame his opponent's final push with a whipped forehand winner, hit sharply cross-court, and an ace up the 'T' - his sixth ace on the day.

Tiafoe won 75 per cent (24/32) of his first-serve points, although he later noted his serve as an area to improve entering the weekend as he seeks more free points.

With the win in this meeting of first-time Tokyo quarter-finalists, Tiafoe advanced to his fourth semifinal of the season following deep runs in Estoril, Atlanta and the US Open. He is seeking his first title of 2022.

The American has not dropped a set in his three matches in Tokyo, defeating Japan's Yasutaka Uchiyama in the opening round and Spain's Bernabe Zapata Miralles in the second round.

By reaching the semifinals, Tiafoe moved up two places to No. 17 in the Pepperstone ATP Live Rankings, which would set him up for a new career high. But several players just below the American can still finish the week above him, including Nick Kyrgios and Denis Shapovalov in Tokyo.

"It's cool. My ranking's going in the right direction... The work is finally paying off." Tiafoe said of his rise in the past month. But his motivation continues to come from within, with a more granular focus on winning matches and titles.

"To be brutally honest, my ranking is cool and everything, but I just want to win the biggest titles in the world. Wherever my ranking sits is great, but I know what I'm capable of," he added.

Kecmanovic was seeking his third semi-final of 2022 and the first of his career above the ATP 250 level. The Serbian saved six match points -- including one with a tweener -- to shock eighth seed Daniel Evans in the second round after knocking out Japanese No 1 Yoshihito Nishioka in his opening match.

Next up for Tiafoe will be Soonwoo Kwon, who scored a bagel set of his own in a 6-3, 6-0 win against Pedro Martinez. The South Korean upset sixth seed Alex de Minaur in straight sets the opening round before a three-set win against Mackenzie McDonald.

"Kwon is a great player. He's been playing really well this week," Tiafoe said of his semifinal opponent, noting that the pair have practised together in Florida.

The American won their lone previous ATP Head to Head meeting in the opening round of the Tokyo Olympics, earning his first Olympic singles match win 6-3, 6-2 in the opening round.