San Francisco Frontiers - Nakashima ousts top seed de Minaur and Osaka advances at Washington

De Minaur, the world number six from Australia, fell to American Nakashima 7-6 (7/5), 6-4 in a rematch of last year's Washington quarter-final.

"He came out with some great serving, a lot of first serves," the top-seeded Aussie said. "I played at a high level. I just threw in two pretty awful games on my serve.

"It's a little bit frustrating, but you live and you learn."

World number 33 Nakashima booked a Saturday semi-final against the winner of a later all-American match between 10th-ranked Taylor Fritz and world number 40 Alex Michelsen.

World number three Pegula, an American who won her first career WTA title at Washington in 2019. eliminated 20th-ranked Anna Kalinskaya 6-3, 7-5, to reach her sixth WTA semi-final of the year.

"Since the beginning of the year I'm finding more confidence in matches hitting different spots," Pegula said. "I was focusing on that a lot today."

Pegula will face the winner of a later match between Russians Diana Shnaider and Liudmila Samsonova on Saturday for a berth in Sunday's final.

Japan's third-seeded Osaka, a four-time Grand Slam winner, rallied to eliminate Italy's Elisabetta Cocciaretto 4-6, 6-4, 6-3 after two hours and 11 minutes.

World number 13 Osaka reached a semi-final against the winner of a later match between Ukraine's second-seeded Elina Svitolina and Alexandra Eala of the Phillipines.

"In the first set, I had low energy and I kept trying to pump myself up but something was a little flat," Osaka said. "In the second, I just wanted to give it my best shot even though I wasn't playing too good."

Nakashima, whose only ATP title came at San Diego in 2022, never trailed de Minaur in the tie-break and fired his eighth of 10 aces to take the first set.

Nakashima broke in the ninth game of the second set then held on a service winner to end matters after one hour and 54 minutes.

- 'That's the match' -

"I was probably playing better, having better stats on top in the first set, and it just slipped away," de Minaur said. "In the second set I've got my chances. Break points, just can't convert. All of a sudden I throw in a bad game, and that's the match."

Nakashima saved six of seven break points he faced in improving to 3-1 in their personal rivalry, including a Queen's quarter-final triumph in June.

Pegula seeks her 12th career WTA crown and third of the year after triumphs in Dubai and Charleston.

She broke in the fourth game and held from there to take the first set in 37 minutes then broke in the 11th game of the second set and held at love to advance.

Osaka was undone by 18 unforced errors, three times as many as her rival, in dropping the first set after 41 minutes.

She reached a third set when Cocciaretto double-faulted away a break in the 10th game of set two.

Osaka hit a backhand winner to break in the second game of the final set and held from there.

A.Smith--SFF