Osaka, Fernandez among unseeded stars in the mix

A week ago, Karolina Pliskova had a terrific run at the Transylvania Open, winning five matches and her first title in four years. And then, after a 10-hour flight from Cluj-Napoca, Romania to Doha, Qatar, she grabbed four hours of sleep and began the process all over again.

After winning a trio of three-set matches, Pliskova will meet resurgent Naomi Osaka in a Thursday quarterfinal at the Qatar TotalEnergies Open. It will be Pliskova’s ninth match in 10 days.

The Czech Republic’s Pliskova, who turns 32 next month, is only one of a handful of surprises in the final eight of this Hologic WTA Tour 1000 event. No.1 Iga Swiatek and No.3 Elena Rybakina are the only seeded players remaining in the draw.

While Victoria Azarenka isn’t seeded, this is her 36^th WTA 1000 quarterfinal, tied for No.3 all-time with Petra Kvitova and Caroline Wozniacki. Azarenka’s straight-sets win over Jelena Ostapenko was her 22^nd in Doha, equaling Kvitova’s leading total since the tournament’s inception in 2001.

Azarenka will now face Swiatek in a quarterfinal match between two-time Doha champions. Swiatek leads the head-to-head 2-1.

A brief accounting of the other unseeded competitors and their Thursday matchups:

Leylah Fernandez — The Canadian teenager blazed into our consciousness by sweeping into the finals of the 2021 US Open. Since then, Fernandez’s record in Grand Slams is 9-8.

So, after stunning Zheng Qinwen 7-5, 6-3, how does the No.38-ranked player find herself on the threshold of her first WTA 1000 semifinal? The power of positivity.

Fernandez trailed Zheng 5-3 in the first set and came back to win four straight games with some great defense and sharp angles.

“We’ve been working a lot on staying positive in tough moments, trying to change the mentality from negative to positive,” Fernandez said afterward. “Especially 5-3 down, I looked at my box and they looked at me and pointed to their head and I knew exactly what that meant.

“And I guess that just changed the whole process in how the match went. Zheng Qinwen, she’s off to an amazing start for the year. Finals of a Grand Slam, Top 10 — so it’s not very easy to play against a player like that.”

Now 21, Fernandez’s next assignment won’t be easy, either. It’s her first up-close, across-the-net look at No.3 seed Rybakina.

Naomi Osaka — For the record, she’s ranked No.747, but that’s only because she left the Tour for an extended maternity break.

Understandably, the four-time Grand Slam champion looked a bit sluggish in her return, losing three of her first four matches. In Doha, however, she has been in encouraging form.

In the opening round, she avenged her first-round Australian Open loss to Caroline Garcia. That was followed by a three-set win over Petra Martic and a walkover in the third round when Lesia Tsurenko pulled out with an elbow injury.

“Honestly after Abu Dhabi [and a…