From match-point saves to a marathon encounter that finished close to midnight, Wednesday at the Galaxy Holding Group Guangzhou Open was a wild ride as all eight second-round matches were completed.

Start of play was delayed by nearly two hours due to suspension for heat, but despite the humid conditions both Viktoria Hruncakova and Greet Minnen battled for over 3 hours to seal their wins. No.7 seed Minnen reached her first tour-level quarterfinal since Prague 2021 by defeating qualifier Harriet Dart 7-6(7), 6-7(5), 6-4 in 3 hours and 14 minutes, before lucky loser Hruncakova closed out the day with a 7-6(5), 5-7, 6-4 triumph over wild card Yuan Yue in 3 hours and 29 minutes.

Photos: All this year's 3-hour matches

Minnen and Hruncakova also exemplified the variety of styles on show in the last 16. Minnen and Dart both showcased all-court games in which the player who was able to get to net more often invariably seized momentum.

Highlights: Minnen d. Dart

"We both left it all out there today," said Minnen afterwards. "It's very tough conditions. Thank God the sun went down at the second set and we could play a bit in the shade and dark -- that helped a little bit. The courts are very fast, which I like."

By contrast, Hruncakova and Yuan dealt in all-out power. The No.128-ranked Slovak crunched 90 total winners, including 15 aces, as she made her way into her second quarterfinal of 2023. Yuan battled hard in her attempt to reach a maiden WTA quarterfinal, but Hruncakova finally found another blistering forehand to convert her seventh match point. Despite the loss, Yuan greeted her at net with a broad smile to recognize the marathon they had both been through -- the joint-eighth longest WTA main-draw match of the season so far.

Highlights: Wang Xiyu d. Shnaider

There will be home representation in the last eight, though, after Wang Xiyu edged Diana Shnaider 6-4, 7-5 to reach her first WTA quarterfinal since Cluj-Napoca last October. In a battle of big-hitting left-handers in which 73% of the rallies lasted under five shots, Wang had the edge on serve, landing more first serves and winning a greater percentage of those points.

"She's a young and dangerous player," said Wang afterwards. "She has really good shots, and she's physically really strong too. So I'm just trying to run some shots and do my best."

Wang wll next play Hruncakova, whom she has defeated three times in as many previous meetings -- including a 4-6, 6-3, 7-6[6] first-round tie at the US Open last month. Minnen will play No.4 seed Lucia Bronzetti, who came through 6-3, 6-3 against Japanese qualifier Moyuka Uchijima.

Highlights: Masarova d. Golubic | Linette d. Saville

Elsewhere, No.5 seed Rebeka Masarova also emerged on top of a rollercoaster match 6-1, 3-6, 7-6(7) over qualifier Viktorija Golubic. The Spaniard trailed 5-3 in the third set, but saved three match points on her own serve in that game, and a further two in the deciding tiebreak, before quelling Golubic's creativity. Masarova will next play No.1 seed Magda Linette, who survived a significant second-set improvement from Daria Saville to win 6-0, 7-6(0).

Photos: All of 2023's wins from match point down

The last quarterfinal will pit two of the tour's premier exponents of the slice and the drop shot against each other. No.3 seed Tatjana Maria has dropped just six games in two matches so far, and needed only 66 minutes to dismiss wild card Bai Zhuoxuan 6-1, 6-2. Yulia Putintseva advanced after Clara Tauson was forced to retire trailing 3-6, 7-6(5) due to heat illness.

After losing the first set, Putintseva had shown typical grit to cling on in the second, staving off all eight break points she faced before converting her fifth set point. A distressed Tauson required medical treatment after the second set; after double faulting in the first game of the third, she collapsed into the ground and eventually had to leave court in a wheelchair.