Brandon Nakashima sinks Frances Tiafoe in Tokyo before Ben Shelton denies Reilly Opelka

While defending Tokyo champion Ben Shelton managed to turn things around against a fellow American Thursday, Frances Tiafoe was unable to do the same.

An in-form Brandon Nakashima confidently defeated the seventh seed, 7-5, 6-3. Though Tiafoe secured the first break midway through the opening set, he couldn’t consolidate the advantage.

From there, Nakashima proved to be the superior server. The San Diego, Calif. kept his countryman from creating another break point, finishing with 12 aces in the 82-minute victory.

Nakashima, ranked a career-high No. 36 this week, has proven to be a tough out of late. In addition to Tiafoe, the 23-year-old has bested compatriots Taylor Fritz and Tommy Paul within the past two months—all on hard courts—whilst also securing wins over Holger Rune and Lorenzo Musetti en route to the US Open round of 16.

France’s Ugo Humbert awaits Nakashima in round two.

Meanwhile, Shelton fended off Reilly Opelka with his 3-6, 6-1, 6-4 victory. After falling behind a set, the left-hander regrouped by converting three breaks to swiftly get himself back on even terms.

In the decider, it was smooth sailing for the server until the eighth game. Opelka would save three break points to reach 4-4, but when the question was asked again the next time he was at the line, an erratic mid-court forehand flew long to dash the former world No. 17’s hopes of extending the clash any further.

Shelton also dropped the opening set of his first-round match during his maiden ATP title run last October at the Ariake Tennis Park, a milestone moment that followed his first trip to a Grand Slam semifinal in New York. The 21-year-old is now 13-15 this year in matches where he dropped the first set.