Bartunkova, 19, shows off 'Federer, Alcaraz style' to upset Bencic at AO

Nineteen-year-old Czech qualifier Nikola Bartunkova produced the first Top 10 upset of the Australian Open late Thursday night, ending No. 10 seed Belinda Bencic’s 12-match winning streak with a 6-3, 0-6, 6-4 victory. Playing in her first Grand Slam main draw, Bartunkova mixed pace and precision to pull through a three-set test.

Australian Open: Scores | Draws | Order of play

"It's a dream come true, because it was an unbelievable match from me," Bartunkova said afterward.

The gap in experience was significant. Former Olympic gold medalist and two-time major semifinalist Belinda Bencic, 27, had not lost a match since October. At the United Cup two weeks ago, she went unbeaten in singles, prompting Swiss teammate Stan Wawrinka to say that everyone was “living in Belinda’s world.”

By contrast, Bartunkova exited the Canberra WTA 125 earlier this month after winning just three games in a 6-1, 6-2 first-round loss to Tatiana Prozorova.

A former Top 10 junior, Bartunkova has climbed from No. 537 to No. 126 over the past year and had never played Grand Slam qualifying before last week. Bencic was the first Top 20 opponent she had faced.

Still, Bartunkova’s 7-6(7), 0-6, 6-3 first-round win over Daria Kasatkina signaled more than a one-off result. Over 2 hours and 12 minutes on ANZ Arena, she backed it up with another composed performance, this time against a Top 10 seed.

"My tennis is unpredictable," Bartunkova told iSport.cz last year after reaching her first WTA semifinal in Guadalajara. "I hit something different each time so rivals don't know what ball is coming."

That was something Bencic learned.

Bartunkova showed a full range of shot-making on the WTA Tour Driven by Mercedes-Benz, finishing with 40 winners that came from all areas of the court. She struck flat, aggressive drives down the line, mixed in well-timed drop shots and consistently looked to finish points at the net. Bartunkova won 17 of 26 points when moving forward, using quick reflexes to take time away from Bencic.

"Federer style, Alcaraz style," Bartunkova said when asked about the variety she brought to the court. "All the more aggressive players -- that's my inspiration since I was a kid. "I like playing the volleys, the drop shots, everything, because I know that opponents don't like it much. So that's why I play it!"

Bartunkova raised her level on the biggest points. She earned a break for 4-2 in the first set with sharp exchanges at the net and set up her first set point with a backhand winner down the line. Serving at 3-2 in the third set, she faced two break points but answered with a service winner and a forehand struck down the line from a stretched position. After holding for 3-3, she created another break chance with a series of low slices and converted it by moving forward aggressively on the return.

She showed composure down the stretch as well. Bencic broke back to level the third set at 4-4, but Bartunkova responded with two clean return winners and another backhand down the line. Serving for the match, she closed it out with a well-timed drop shot and passing combination.

Bartunkova will next face No. 21 seed Elise Mertens, who defeated Moyuka Uchijima 6-3, 6-1, as she bids to keep her dream debut alive.

Valentova wins all-Czech derby; to face rematch with Rybakina

Bartunkova wasn't the only Czech teenager to impress on Thursday. Tereza Valentova, 18, came through a 2-hour, 41-minute match in a first meeting with 20-year-old compatriot Linda Fruhvirtova 7-5, 2-6, 6-3 to advance to the third round of a Grand Slam for the first time.

Ranked at a career high of No. 54 this week, Valentova is contesting her first senior Australian Open, and just her seventh tour-level main draw overall. But she is already a WTA finalist, having been runner-up in Osaka last October, and she outlasted Fruhvirtova with superior aggressive weapons and greater variety. Valentova saved four set points in overturning a 5-3 first-set deficit, and tallied 35 winners to her countrywoman's 17.

Her reward will be a second shot at No. 5 seed Elena Rybakina, who came from 3-1 down in the first set to defeat Varvara Gracheva 7-5, 6-2. The pair previously met in the second round of the US Open last year; Valentova held a 5-2 lead, and four set points, in the second set before falling 6-3, 7-6(7).

In total, five teenagers have made it to the Australian Open third round this year. Bartunkova and Valentova join 19-year-old Victoria Mboko and 18-year-olds Mirra Andreeva and Iva Jovic in the top half of the draw. The last time a Grand Slam third round featured five teenagers was the 2009 US Open, which included 19-year-olds Petra Kvitova, Yanina Wickmayer, Caroline Wozniacki and Sorana Cirstea, and a 17-year-old Melanie Oudin.