The plethora of Czech talent on the Hologic WTA Tour has descended upon the Miami Open, and six of their players reached the third round this fortnight.
Coincidentally, those six women were all in the bottom half of the draw, and all of their third-round matches took place on Sunday.
One of those six Czechs, No.31 seed Marie Bouzkova, lost to No.2 seed Aryna Sabalenka 6-1, 6-2 in the marquee night match, but three Czechs did win on Sunday. Here is how the rest of the compatriots fared:
 Petra Kvitova (CZE) def.  Donna Vekic (CRO) 6-4, 7-6(3)
In a clash between Top 20 players on the Grandstand court, World No.12 Kvitova held off 20th-ranked Vekic in 1 hour and 39 minutes to reach the Miami Round of 16 for the sixth time in her career, and the fifth time in her last five appearances at the tournament.
"I think the secret was to stay focused on every point, especially in the second set," Kvitova said after her win. "She was always coming back after a [service] break, and it wasn't really easy already in the first set. ... It was very difficult, she played very well, she served very well."
Kvitova and Vekic each had 19 unforced errors, but Kvitova negated that total with 19 winners, while Vekic had 14 winners. Each player was perfect converting all of the break points they held, but Kvitova's one extra break in the first set made the difference on Sunday.
Current Czech No.1 Kvitova now has a 4-1 head-to-head lead on Croatia's Vekic, with three of those four wins coming in Miami Open third-round matches. Kvitova also beat Vekic here in the same round in both 2014 and 2019.
Kvitova, who is playing the 99th WTA 1000 tournament of her career, will square off against qualifier Varvara Gracheva for the first time in Monday's Round of 16.
 Barbora Krejcikova (CZE) def.  Madison Keys (USA) 7-6(4), 6-3
Czech No.2 Krejcikova gritted through two long sets before toppling American Keys in just under two hours. With the win, 2021 Roland Garros champion Krejcikova avenges her loss to Keys in their only previous meeting, in the 2022 Australian Open quarterfinals.
Krejcikova did not convert two set points at 5-4 in the opener, but she was able to take the tiebreak after an hour of play. A topsy-turvy second set was defined by a 15-minute game at 3-3, in which Krejcikova saved seven break points before holding. Krejcikova did not lose another game.
Keys finished the match with 26 winners to Krejcikova's 17, but the American also had 10 more unforced errors than Krejcikova in the clash. Krejcikova, who won the title at this year's first WTA 1000 event in Dubai, is now 10-1 at WTA 1000-level so far this season.
Krejcikova will now play No.2 Aryna Sabalenka for the third time this season, and at every WTA 1000 event so far this year. Krejcikova upset Sabalenka in the Dubai quarterfinals en route to the title, but Sabalenka got her revenge last week in the Indian Wells Round of 16.
Marketa Vondrousova (CZE) def.  Karolina Pliskova (CZE) 6-1, 6-2
In the only all-Czech battle of the day, Vondrousova needed just 52 minutes to charge past former World No.1 Pliskova. Pliskova made a slight fightback with her back against the wall, winning two games in a row from 5-0 down in the second set, but otherwise it was one-way traffic for left-handed Vondrousova.
2019 Roland Garros finalist Vondrousova, who missed six months of action last year following wrist surgery, has reached the Round of 16 at both of this year’s Sunshine Double tournaments as her comeback continues. Earlier this month, Vondrousova beat No.4 seed Ons Jabeur in Indian Wells before falling to her countrywoman Karolina Muchova.
Sorana Cirstea (ROU) def. [Q] Karolina Muchova (CZE) 7-5, 6-1
Romania’s Cirstea also extended a Sunshine Double surge with a win over Czech Muchova on Sunday. Muchova served for the first set at 5-4, but Cirstea broke the Czech at love in that game before steamrolling to the 91-minute win, reaching the Miami Open Round of 16 for the first time in exactly 10 years.
Cirstea made the quarterfinals last week in Indian Wells, and she has beaten World No.4 Caroline Garcia in both Indian Wells and Miami this month. Those upsets mark the first time 32-year-old Cirstea has garnered multiple Top 5 wins in a single season.
Cirstea will next play Vondrousova for her chance to make back-to-back WTA 1000 quarterfinals. Vondrousova won their first meeting at the 2021 Australian Open in straight sets, but Cirstea leveled their rivalry with a three-set win at St. Petersburg last year.