Daria Kasatkina continued her strong start to 2022 by upsetting No.2 seed Garbiñe Muguruza 6-4, 6-4 at the Sydney Tennis Classic to reach her second semifinal in as many weeks.

Kasatkina, who reached the last four at Melbourne Summer Set 2 last week before losing to Amanda Anisimova, has yet to drop a set in Sydney. This efficiency has snapped the run of four three-setters the Russian has played against Muguruza dating back to 2017. Her first straight-sets win of their rivalry levels the overall head-to-head at three apiece.

The victory is also Kasatkina's first Top 5 win since defeating Caroline Wozniacki in the fourth round of Roland Garros 2018, and her ninth overall. Last year marked a renaissance for the former World No.10, who bounced back up the rankings from No.71 to No.26 after winning two titles (Phillip Island Trophy, St. Petersburg) and reaching a further two finals (Birmingham, San Jose).

Daria Kasatkina's career Top 5 wins
d. Angelique Kerber 7-6(5), 6-2, R2 Sydney 2017
d. Angelique Kerber 6-4, 0-6, 6-4, R2 Doha 2017
d. Simona Halep 6-2, 6-1, R2 Wuhan 2017
d. Caroline Wozniacki 7-6(2), 6-3, QF St. Petersburg 2018
d. Garbiñe Muguruza 3-6, 7-6(11), 6-1, SF Dubai 2018
d. Caroline Wozniacki 6-4, 7-5, R4 Indian Wells 2018
d. Garbiñe Muguruza 6-2, 4-6, 6-3, R3 Madrid 2019
d. Caroline Wozniacki 7-6(5), 6-3, R4 Roland Garros 2018
d. Garbiñe Muguruza 6-4, 6-4, QF Sydney 2022

Turning points avoided: The past four editions of Kasatkina's rivalry with Muguruza have been characterised by wild twists and turns, with each scoring one win over the other from match point down. That was not the case this time, though the second set teetered on the edge of the possibility.

In the first set, Kasatkina delivered a watertight performance on serve, an area of her game that has been vulnerable in the past. The 24-year-old landed 67% of her first serves, won 83% of those points and did not face a break point. In the fifth game, she captured the Muguruza serve as the Spaniard sent a backhand long for the only break of the set.

Matters were more complicated in the second set as Kasatkina's first-serve percentage dropped to 57%. Three times she went up a break, and twice she was broken back. Even when she consolidated her break for 4-2, she wasn't home and dry. Kasatkina missed triple break point for a 5-2 double break, and on her first match point committed a fourth double fault, decelerating on her second serve so much that it drew gasps from the crowd.

But off the ground, Kasatkina repeatedly produced moments of magic in important moments. A defensive pass to break for 2-1 in the second set was a phenomenal piece of shot-making that she celebrated with an equally athletic leap into the air, and she moved up 5-3 after some superb scrambling finished with a backhand laser down the line.

A tactical adjustment from Muguruza to swarm the net at every opportunity paid some dividends in the second set, but not enough to offset her 40 unforced errors. The WTA Finals champion was unable to hit through Kasatkina consistently, and in the second set would commit wild mistakes at crucial times on the smash and drop shot as well.

In Kasatkina's words: "I think this is the best start of my career ever," she said afterward. "I think I never start the season that well. To win always feels amazing. Doesn't matter if you are winning the matches right before a slam and you maybe feel you're tired - it doesn't matter, because better you win the matches than you lose first round, and then you go and you have one week to practice, but for what? You have been practicing the whole preseason.

"So the most important is the confidence, and you get it by winning matches. This is the most important, because at the end, OK, tiredness can affect of course, but the most important is to feel confidence while you're playing."

Badosa maintains perfect record against Bencic

Kasatkina will face No.5 seed Paula Badosa next in a Generation 1997 semifinal clash. It will be the second straight opponent also born in 1997 for the Spaniard, who overcame Belinda Bencic 7-6(6), 3-6, 6-3 in 2 hours and 35 minutes.

Though Bencic enjoyed the more glittering junior career, Badosa has dominated their professional rivalry, adding a third win in as many meetings to go with her victories over the Swiss player in Charleston and Madrid last year. Their first hardcourt encounter was the hardest-fought yet, though.

Badosa led 5-3 in the first set, but ultimately needed six set points to close out Bencic, who was contesting her second match of the day after completing a rain-delayed comeback over Océane Dodin earlier. Despite coming out on the wrong end of the first-set tussle, the Olympic gold medallist bounced back to take the second thanks to a slew of dropshots. However, Badosa proved stronger in the closing stretch as Bencic faded somewhat.

"The key was to stay fighting until the end, like I always try to do," Badosa said. "Accepting her good moments, because I think she played amazing and I had a lot of chances and I wasn't taking them. Then I think in the third set I was going for it, very aggressive, and that's what gave me the match."

The semifinal will be a first-time pro encounter for Kasatkina and Badosa. The pair last played in the fourth round of the 2013 U16 European Junior Championships in Moscow, with Kasatkina winning 2-6, 6-2, 6-2 en route to winning the title over Jil Teichmann in the final.

Kasatkina did not recollect that match, but both spoke about the camaraderie they shared growing up at tournaments together.

"It's always nice to have these kind of stories where you start playing some Tennis Europe tournaments and U12 together," Kasatkina said. "And out of nowhere, you're playing semifinals in the big tournaments against each other."

Badosa agreed with the sentiment.

"I have pictures of [us at] 13 years old together," she said. "We were very close friends when we see each other in tournaments. I know her family and everything. She's a very nice girl. I'm happy that we both made it here. It's nice to see her as well here, playing in the semifinals now."