ST. PETERSBURG, Russia – With the toils and warmth of the Australian summer drifting into the distance, and after a frenetic Fed Cup weekend, the manic month of February on the WTA calendar has begun, with many of the top female stars heading to Russia for the St. Petersburg Ladies Trophy.

Four of the WTA’s Top 20 took their place in the singles draw this week – Grand Slam winner Ana Ivanovic, Slam finalists Caroline Wozniacki and Roberta Vinci, and top-seeded Belinda Bencic – and three have successfully negotiated their way into the last eight. Let’s analyze the four Friday match-ups which will attempt to wow the home Russian crowd…

[1] Belinda Bencic (SUI #11) vs. [5] Anastasia Pavlyuchenkova (RUS #26)
In her first tournament as the No.1 seed, Belinda Bencic certainly struggled early-doors in her opener against Annika Beck. But, as top players do even on an off day, the Swiss battled through in straight sets, 7-6(3), 6-3.

At just 18, Bencic already has 11 victories over Top-10 opponents – most recently over Angelique Kerber in last weekend’s Fed Cup – and now sits on the verge of making that breakthrough into the Top 10 herself. Two more wins this week would propel the Swiss past Carla Suárez Navarro and into the No.10 spot for the first time in her young career.

First though, she’ll have to get past home favorite Anastasia Pavlyuchenkova in Friday’s quarterfinals, after the Russian defeated Carina Witthoeft, 6-1, 7-5, in the second round.

Bencic and Pavlyuchenkova have clashed twice before, with the meetings split one apiece. The latter won most recently in Washington in 2015, while Bencic triumphed on the Rome clay in three sets the year before.

Dominika Cibulkova (SVK #66) vs. Daria Kasatkina (RUS #63)
Eighteen-year-old Russian Daria Kasatkina is certainly raising some eyebrows in the tennis world right now, with many billing her as a potential elite player for the next decade.

She’s leaping up the rankings: at the end of 2014, she sat at No.370; by 2015’s close, she had sprung up to No.72. As a lucky loser at the US Open last year, she won through to the third round. Then, in Moscow she came through qualifying to reach the semis.

After scoring her first Top-10 win in Auckland (over Venus Williams), Kasatkina is at it again at home in Russia, storming through to the last eight to face former World No.10 Dominika Cibulkova.

Cibulkova, the 2014 Australian Open finalist, has been the dangerous, unseeded landmine in tournament draws for a year or so now, after her ranking dropped through injury. The Slovakian inflicted another blow on Caroline Wozniacki’s stuttering start to 2016, with a 6-4, 7-5 win on Thursday.

This should be a fascinating match-up between two players of similar ranking but with hugely different experiences on a tennis court to date. Both bring controlled aggression on their groundstrokes so it’ll be intriguing to see who can rein in the errors to gain the upper hand from the baseline.

[Q] Kateryna Kozlova (UKR #177) vs. [3] Ana Ivanovic (SRB #20)
Moving to the draw’s bottom half, 21-year-old World No.177 Kateryna Kozlova is undoubtedly the week’s surprise package thus far. The Ukrainian qualified for the main draw and now finds herself in the quarterfinals after impressive wins over Barbora Strycova and Elena Vesnina.

After loitering around on the ITF circuit for the past few years, she now finds herself up against one of the game’s iconic names. After storming back up the rankings in 2014, Ana Ivanovic had a disappointing year at the showpiece events in 2015; excluding a run to the semis at Roland Garros, she only won one more match at the other three majors combined.

She started well at the Australian Open but endured a difficult third-round contest with Madison Keys, as British coach Nigel Sears collapsed during play and had to be taken to hospital. The Serb was subsequently beaten in three sets by the young American.

But Sears is back in business now and so is his charge, as Ivanovic dealt well with talented Russian Margarita Gasparyan in the second round in St. Petersburg. Ivanovic will likely have too much experience and firepower for the young Ukrainian, as they match-up for the first time on Friday.

Timea Babos (HUN #51) vs. [2] Roberta Vinci (ITA #16)
After that captivating run to the US Open final last year, Roberta Vinci wouldn’t have been thrilled to exit Melbourne in the third round to Germany’s Anna-Lena Friedsam. So the Italian will be looking to have a strong couple of months now to build on the back end of 2015, starting in St. Petersburg.

This is a tussle between two high-quality doubles players, who have actually met in a Grand Slam final, back in 2014 at Wimbledon (where Vinci and Sara Errani defeated Babos and Kristina Mladenovic in straight sets). Both are comfortable playing all over the court, which should produce a match full of variety. Vinci will look to unsettle Babos’ power game though with her slice, as she famously did to Serena Williams in New York.

World No.51 Babos will be at a new career-high ranking whatever happens next week, after a good win over No.9 seed Monica Niculescu in the second round. She had a decent run in Shenzhen before the Australian Open too, reaching the semis.

Vinci leads the head-to-head between them 3-1, winning their last encounter on the Bucharest clay in 2015.

Who’re your picks to make the semifinals?

Join us in St. Petersburg on Friday and watch all four quarterfinals from the inaugural St. Petersburg Ladies Trophy on WTA Live powered by TennisTV.