World number one Novak Djokovic cruised into the semi-finals of the ATP and WTA Western & Southern Open on Wednesday by routing Germany's Jan-Lennard Struff 6-3, 6-1.
Djokovic, who launches his bid for a fourth US Open title and 18th Grand Slam crown on Monday, needed only 62 minutes to advance to a Thursday semi-final against Spain's Roberto Bautista Agut, who upset defending champion Daniil Medvedev, last year's US Open runner-up from Russia, by 1-6, 6-4, 6-3.
Djokovic had no issues with a prior neck injury as the 33-year-old Serbian tested himself well on the Flushing Meadows hardcourts in the same spectator-less Covid-19 bubble quarantine atmosphere where the US Open will be played.
"It was great. I feel very good," said Djokovic who is 21-0 this year.
"Started a little bit tight the opening couple of games of my service games. Managed to defend well.
"Ever since that first break early in the first set, I never looked back. I really played very aggressive when I have a chance. I was playing my shots. I was very pleased with my serve."
Djokovic won the title of the event typically played in Cincinnati in 2018 after five prior finals losses and looks like he could claim a second title in three tries while warming up for the US Open and testing the improvements made to his games since the Covid-19 shutdown.
"Everything was worked on in the last six months," he said.
"Looked into what can be upgraded. I worked on every single shot. It's good that it's paying off so soon after the break. Hope to keep it going."
Bautista Agut, ranked 12th, fought back after being blasted in the first set.
"It was a very good comeback," said Bautista Agut. "I changed my rhythm with the ball. I tried to do some different things with the slice. I had some good volleys.
"It was a fantastic comeback for me. I had to fight a lot to stay there in the second set. It was a really tough match. I'm glad to get through."
His reward is an on-form Djokovic, who has won five of the past seven Grand Slam titles as he chases Roger Federer and Rafael Nadal -- both absent from the New York bubble -- for the all-time Slam title record.
"Everybody knows Novak? I don't think he has lost all year," Bautista Agut said.
"He's very solid. I'll try to play my best game against him. If I can play a good level, it's going to be a good match."
Djokovic respects the Spaniard, who has won three of their 11 encounters.
"He doesn't give it easy," Djokovic said. "You have to earn your points. Very solid. Roberto found a way (to win), obviously a virtue of champions."
The other semi-final will send Greek fourth seed Stefanos Tsitsipas, who advanced down 5-6 when American Reilly Opelka retired, against the winner of a late match between Canada's Milos Raonic and Serbian Filip Krajinovic.
- Osaka battles back -
On the women's side, two-time Grand Slam champion Naomi Osaka of Japan battled back to defeat Estonia's Anett Kontaveit 4-6, 6-2, 7-5.
The Japanese fourth seed will play a semi-final Thursday against Belgian 14th seed Elise Mertens, who eliminated American Jessica Pegula 6-1, 6-3.
Osaka, the 2018 US Open and 2019 Australian Open champion, reached her second WTA semi-final of the year after Brisbane in January.
After being broken to trail 0-2 in the second set, Osaka reeled off nine straight games to seize command on her way to winning in an hour and 52 minutes.
Osaka is 1-1 in her career rivalry with Mertens, winning their most recent matchup in last year's Osaka semi-finals.
Also into the last four was two-time Australian Open winner Victoria Azarenka of Belarus, who beat Tunisia's Ons Jabeur 7-6 (11/9), 6-2.
She will play for a spot in the final against British eighth seed Johanna Konta, who advanced 6-4, 6-3 in 92 minutes over Greece's 13th-seeded Maria Sakkari, who defeated Serena Williams in the round of 16.