Russian veterans Svetlana Kuznetsova and Vera Zvonareva took disparate paths into the quarterfinals of the St. Petersburg Ladies Trophy on Wednesday.

Former World No.2 Kuznetsova withstood a second-set surge by 19-year-old qualifier Wang Xinyu and claimed a 6-1, 7-5 victory in just over an hour.

But earlier in the day, Zvonareva, another former World No.2, was pushed to three hours and 10 minutes of grueling action before upending No.3 seed Fiona Ferro, 6-7(6), 7-5, 7-6(2).

35-year-old Kuznetsova has now reached her first WTA quarterfinal in over a year, since she made it into the semifinals at 2020 Doha last winter.

Wang exhibited solid aggressive play during their tilt, with slightly more than double Kuznetsova's winner and unforced error totals, but it was the Russian who was stronger on break points, converting six of the nine she held.

Svetlana Kuznetsova serves during her second-round match at the St. Petersburg Ladies Trophy.

Photo by WTA/Jimmie48

No.4 seed Kuznetsova zipped through the early stages of the match with ease, knocking off nine of the first ten games to reach 6-1, 3-0. But things got slightly dicey for the Russian as Wang's powerful shots found the court more regularly, and Wang earned her first break of the day to get back on serve at 3-2.

Kuznetsova served for the match at 5-3 but Wang broke once more, slamming a winner down the line to pull back on serve again. But Wang was undone while serving to stay in the match at 6-5 -- she hit two consecutive double faults to give Kuznetsova a match point, which the Russian converted after a forehand miscue by the qualifier.

2021 St. Petersburg Highlights: Zvonareva outlasts Ferro in over 3 hours

36-year-old Zvonareva, a Wimbledon and US Open finalist in 2010, moved into her first WTA-level quarterfinal since reaching the semifinals at this very event in 2019. Her upset of World No.43 Ferro is her first Top 50 victory since a win over Magda Linette at last year's Western & Southern Open.

An early break lead in the first set for Zvonareva was held through the majority of the opener, and after ending a service hold for 5-3 with three consecutive aces, the Russian was in fine form. But, serving for the set at 5-4, Zvonareva double-faulted away her lead, and Ferro got back level, extending the set into the tiebreak.

In the breaker, Zvonareva had a set point at 6-5, but hard-charging putaways won Ferro the next two points, giving her a 7-6 lead and a set point of her own. There, Zvonareva fired a backhand long, and Ferro had fought all the way back to swipe the one-set lead.

"We both were fighting for every point, trying to hang in there. I think I was able to play some good tennis when it mattered, and I’m happy with the win of course."

- Vera Zvonareva, following her marathon victory

The second set was very nearly a carbon copy of the first, as Zvonareva served at 5-3 only to see herself broken by a Ferro backhand return winner. This time, though, Zvonareva steeled herself when it mattered, converting her third set point to break and tie up the affair at one set apiece. Zvonareva had 16 winners to just six unforced errors in the second set.

In the decider, Zvonareva once again grabbed an early break, this time at 2-0, only to see Ferro strike back in the very next game. There were no more breaks of service en route to the decisive tiebreak, where Zvonareva used her divine footspeed and strong backhand to cruise through the breaker.

The three-hour and 10-minute clash became the longest match in the tournament's history, breaking a record which had ironically been reset in the prior match on Sibur Arena.

In the opening match of the day, the first round was completed with qualifier Anastasia Gasanova's 6-2, 6-7(6), 7-5 victory over Katarina Zavatska.  Gasanova won in three hours and four minutes, which set a new record for the longest match in the event's history -- that is, until Zvonareva and Ferro finished their barnburner.

Gasanova will now take on her compatriot Anastasia Pavlyuchenkova in the second round. The winner of that clash will face Zvonareva in what is already guaranteed to be an all-Russian quarterfinal match.

As a lengthy day stretched further into the evening, No.1 seed Ekaterina Alexandrova kicked off the night session with a 6-3, 6-4 victory over Tereza Martincova, meaning Russians went 4-0 on a triumphant Wednesday in St. Petersburg.

Alexandrova, who reached the semifinals at the event last season, had split her previous meetings with Martincova, but regained the lead in their head-to-head after a straightforward 73-minute win.

The flat, powerful shots of Alexandrova garnered her 19 winners on the day, and though she also fired 17 unforced errors, it was a ratio which well outpaced her opponent's. Martincova had 13 unforced errors and only five winners in the affair.

The top seed charged to a 5-1 lead in the opening set, and even a late break by Martincova to pull to 5-3 did not truly throw off Alexandrova's momentum as she broke to clinch the one-set lead.

A run of four straight service breaks in the second set was halted by Alexandrova with a hold for 5-4, and she used that to her advantage, breaking Martincova for the third time in a row to polish off the victory.

However, the day ended with a big surprise, as qualifier Jaqueline Cristian stunned No.6 seed Jelena Ostapenko, 6-3, 7-6(9).

The World No.160 from Romania collected her upset of the 2017 Roland Garros champion after nearly two hours of play, reaching her first WTA singles quarterfinal in the process.

Seeking her best-ever showing at a WTA event, Cristian faltered and dropped serve in the first game of the match, but that was the qualifier's lone misstep in the opening frame as she broke Ostapenko twice to capture the set.

Cristian had a chance to serve out the match at 6-5 in the second set, where she held her first match point. But thunderous forehands by the power-hitting Ostapenko allowed the former World No.5 to erase that chance, and Ostapenko eventually broke serve to set up a crucial tiebreak.

A tops-turvy breaker saw Cristian lead 3-1 before Ostapenko reeled off five straight points to reach 5-3. However, Cristian herself then won three points in a row to reach 6-5 and a second match point.

More aggressive play by Ostapenko saw her stave off that match point, as well two more at 7-6 and 8-7, and the No.6 seed grabbed a set point of her own at 9-8. But a sturdy serve by Cristian pulled her to 9-9, and she eventually claimed the final three points of the tiebreak to collect a signature win.

Cristian will now face a second Grand Slam champion in a row: two-time major winner Kuznetsova in the quarterfinals.