Tommy Paul boosted his Nitto ATP Finals qualification hopes on Wednesday when he earned his 39th win of the season at the Kinoshita Group Japan Open Tennis Championships, matching his previous-best tally (2022).

The American overcame countryman Mackenzie McDonald 6-4, 6-2 at the ATP 500 event to reach his ninth quarter-final of the season and sixth on hard courts.

Paul was strong on serve throughout the 86-minute clash, winning 21 of 22 points behind his first delivery. The fifth seed did not face a break point and showed his athleticism by winning a series of lung-busting rallies where both pulled each other from corner to corner.

“We know each others games really well,” Paul said. “I have known him since I was 11 years old. Knowing him, I know I have to keep my foot on the gas as if you give him a little bit he takes a lot.”

Paul will continue the quest for his first title of the season when he takes on Ben Shelton in the quarter-finals. The 26-year-old is 12th in the Pepperstone ATP Live Race To Turin, 515 points behind Rune. If Paul wins his second tour-level trophy, he could rise to ninth if his direct rivals fall early in Tokyo.

Shelton continued his breakthrough season on Tour with a 6-7(5), 6-4, 6-3 win against Jordan Thompson. The 21-year-old American, who reached the semi-finals at the US Open in September, is into his fourth quarter-final of the year.

One of those rivals, Casper Ruud, lost on Wednesday in Japan. The Norwegian is 10th in the Pepperstone ATP Live Race, 220 points ahead of Paul.

That gap will not grow any further this week, though, after Marcos Giron defeated the second seed 6-3, 6-4 in one hour and 21 minutes to set a quarter-final clash against Felix Auger-Aliassime.

Giron rallied from 2-4 in the second set, rolling off the final four games to improve to 1-1 in his Lexus ATP Head2Head series against Ruud. Giron has earned three Top 10 wins, having defeated then-World No. 6 Holger Rune in August and then-World No. 10 Matteo Berrettini in 2020.