Former world number one Naomi Osaka advanced to the semifinals of the Miami Open by beating American Danielle Collins in a set.
The four-time Japanese Grand Slam champion, who is yet to drop a set in the tournament, served 13 aces in a 6-2, 6-1 win that lasted exactly an hour.
Australian Open finalist Collins appeared to struggle with a neck injury throughout the game.
Osaka meets Belinda Bencic from Switzerland in the semifinals.
Olympic champion Bencic beat Australia’s Daria Saville 6-1, 6-2 to reach the last four.
Osaka, who was brought to tears by an adventurer during his second-round trip to Indian Wells this month, is only playing in his fourth tournament since his tennis break in September and has dropped to 77th place in the world rankings.
“It was my first game of the night so I didn’t know what the conditions were, but it was good and the fans were great,” said the 24-year-old.
“I’m glad that, in a way, I don’t have a good ranking, because I’m able to play the matches that I need to play. I feel like I’m the type of person that plays better with more matches, so actually having back-to-back matches benefits me a lot.”
Semi-final opponent Bencic, 25, has also not dropped a set so far in Miami and has beaten Osaka in four of their previous five meetings, most recently at the 2019 US Open .
“I get really emotional when I play people around my age or younger,” Osaka added. “I don’t know if it’s like this thing that I want to be better than them, but I just automatically put a lot of pressure on myself.
“I think my mentality was a very big part in my losses back then. Hopefully, it will be better, because I feel like I have kind of worked through it. So hopefully on Thursday, it will be more about tennis. “