Anett Kontaveit of Estonia was one of the opening-day winners at the J&T Banka Ostrava Open on Monday, as she maintained her flawless record against Sorana Cirstea of Romania. Anastasia Potapova, Paula Badosa, and Sara Sorribes Tormo also clinched first-round victories on Day 1.

In a battle between Top 40 players, World No.30 Kontaveit defeated 37th-ranked Cirstea, 6-4, 6-4 in an hour and a half, improving to 5-0 in their head-to-head and booking a spot in the second round in the Czech Republic.

Watch Highlights: Kontaveit powers past Cirstea in Ostrava opener

The pair had already squared off twice this year, with Kontaveit notching wins in Dubai and Miami. She pulled off the hat-trick for the season, converting six of her eight break points to charge to the straight-set victory.

In the first set, a bevy of backhands helped Kontaveit break Cirstea for a 4-3 lead, but the Romanian struck back right away, coming out on top in a rally with a forehand winner to convert her third break point of the next game and level at 4-4.

But Kontaveit took charge once more, using aggressive play to break Cirstea at love and grab the 5-4 lead. Kontaveit served out the set from there, with her 14 winners out-pacing Cirstea’s nine during that stanza.

Kontaveit eased to a 5-2 lead in the second set, but nearly saw that advantage completely disappear as Cirstea clawed one break back and had 0-40 on the Estonian’s serve at 5-4. But Kontaveit went on a run of points from there to reach deuce, and clinched the next two points with forehand winners to seal victory.

Russian qualifier Anastasia Potapova also moved into the second round, holding off former World No.4 Caroline Garcia of France, 6-2, 7-6(6), after an hour and 46 minutes of play.

World No.92 Potapova saved all three of the break points she faced in the clash, leveling her head-to-head with 60th-ranked Garcia at 1-1. Garcia had won their previous meeting at 2019 Tianjin in three sets, but Potapova held the upper hand this time. 

Potapova had seven fewer unforced errors than Garcia, while also having 30 winners to the Frenchwoman's 26 -- one of Potapova's winners coming via a hotshot forehand dropper at the end of a lengthy rally (see highlight below).

With the win, Potapova notched just her second WTA main-draw win since June. The Russian will next meet No.2 seed Petra Kvitova; a victory over two-time Wimbledon champion Kvitova would give Potapova her second career win over a Top 10 player.

Potapova's sole Top 10 win to date came over then-World No.5 Angelique Kerber in the first round of 2019 Roland Garros.

Watch This: Potapova's stroke of genius in Ostrava

Opening day in Ostrava also featured a strong start by the Spanish contingent, as Top 40 players Paula Badosa and Sara Sorribes Tormo won their opening-round clashes with ease.

No.9 seed Badosa ousted Russian lucky loser Varvara Gracheva, 6-2, 6-2, in just an hour and 13 minutes. It was a measure of revenge for Badosa, who had lost to Gracheva in her most recent match, in the second round of the US Open.

In fact, Gracheva knocked Badosa out of the US Open in each of the last two years. But on the indoor hardcourts of Ostrava, World No.27 Badosa had no trouble with the Russian, winning 77 percent of her first-service points and never facing a break point in the encounter.

Badosa's next opponent will be Kontaveit, in their first meeting.

Sorribes Tormo, meanwhile, made relatively short work of another Russian, qualifier Anastasia Zakharova, 6-3, 6-3, winning in an hour and 37 minutes.

World No.36 Sorribes Tormo, an Ostrava quarterfinalist last season, will now take on Olympic champion Belinda Bencic in the second round, in their first meeting.

19-year-old Zakharova is currently ranked at a career-high World No.222, but is still seeking the first Tour-level main-draw win of her career. The teenager made her WTA main-draw debut in Gdynia earlier this year, and lost in the first round of that event and in Luxembourg last week.