Australian world number one Ashleigh Barty saved a match point as she battled back to defeat Slovakia's Kristina Kucova on Thursday and reach the third round of the ATP and WTA Miami Open.
Top-seeded Barty, the 2019 Miami champion and French Open winner, dispatched 149th-ranked Kucova 6-3, 4-6, 7-5, advancing to a match with another Grand Slam winner, Latvia's 54th-ranked Jelena Ostapenko who beat Belgian Kirsten Flipkens 6-2, 5-7, 6-3.
Barty fired 15 aces, two in a row from 0-40 down in the final game, to defeat Kucova after two hours and 27 minutes.
"There's nothing like coming through a test like that," Barty said.
"It was important in that match to stick to working and trying to figure it out as I went on. (I'm) just really happy I never gave up and happy I gave myself a chance to stay in the hunt."
The 24-year-old Aussie avoided her first three-match losing streak since 2014 after having fallen to Czech Karolina Muchova in last month's Australian Open quarter-finals and American Danielle Collins at Adelaide the following week.
Kucova, whose only win over a top-10 foe came five years ago, forced a third set after Barty sent a forehand long to surrender the lone break of the second set.
In the third, Barty sent a backhand wide to give Kucova a break in the fourth game and a 3-1 edge and they both held serve until Kucova served for the match leading 5-3.
On Kucova's only match point, she missed a weak first serve and Barty smashed the second for a down the line winner.
Kucova sent a backhand long two points later to surrender a break and Barty held then broke for a 6-5 edge only to make three errors to put herself one point from a tie-breaker.
Instead, Barty blasted back-to-back aces up the middle and a backhand winner then swatted a service winner on her first match point for the triumph.
"Mentally you need to stay there to give yourself a chance," Barty said. "I was proud I was able to hang in there when mentally I could have gotten a little loose."
Only Japan's second-ranked Naomi Osaka can overtake Barty for the world number one spot at Miami.
Osaka, who won her fourth Grand Slam title at the Australian Open in February, launches her campaign on Friday in a second-round clash with Australian Aja Tomljanovic.
Third-seeded Simona Halep struggled early but stormed home for a 3-6, 6-4, 6-0 victory over France's Caroline Garcia.
The two-time Grand Slam champion from Romania, ranked third in the world, was playing her first match since a quarter-final loss to Serena Williams at the Australian Open.
After Garcia pocketed the first set with an ace on set point, she broke Halep to open the second and saved three break points to extend her lead to 2-0.
But Halep regained the break to knot the set at 3-3, and after breaking Garcia again in the 10th game roared through the third set.
In other women's second-round action, reigning Roland Garros champion Iga Swiatek beat Barbora Krejcikova 6-4, 6-2, and former world number one Angelique Kerber of Germany steamrolled qualifier Renata Zarazua 6-0, 6-0.
"The score, it's a little bit different than the match was, because [a] few games were really close and tough," said Kerber, who next faces another former world No. 1 in Victoria Azarenka.
Azarenka advanced by walkover after a knee injury forced Laura Siegemund to pull out of their scheduled match.
Men's seeds swing into action Friday, led by top-seeded world No 2 Daniil Medvedev, who takes on Taiwan's Lu Yen-Hsun in the second round.
Russia's Medvedev, runner-up to Novak Djokovic at the Australian Open, overtook Rafael Nadal for No 2 in the world after his triumph in Marseille earlier this month.
Results from ATP/WTA Miami Open on Thursday (x denotes seed):
Yasutaka Uchiyama (JPN) bt Salvatore Caruso (ITA) 6-3, 6-4
Miomir Kecmanovic (SRB) bt Liam Broady (GBR) 7-5, 6-7 (5/7), 6-1
Mikhail Kukushkin (KAZ) bt Jack Draper (GBR) 7-5, 0-0 retired
Sebastian Korda (USA) bt Radu Albot (MDA) 6-3, 6-0
Marin Cilic (CRO) bt Federico Coria (ARG) 6-3, 2-6, 6-4
Lorenzo Musetti (ITA) bt Michael Mmoh (USA) 6-4, 6-4
Thanasi Kokkinakis (AUS) bt Shintaro Mochizuki (JPN) 6-3, 6-3
Tennys Sandgren (USA) bt Pedro Martnez (ESP) 6-4, 2-0 retired
Ilya Ivashka (BLR) bt Kwon Soon-woo (KOR) 7-6 (7/4), 6-7 (4/7), 7-6 (7/3)
Denis Kudla (USA) bt Jrmy Chardy (FRA) 3-6, 6-3, 6-4
Joao Sousa (POR) bt Christopher O'Connell (AUS) 7-6 (8/6), 6-7 (8/10), 7-5
Jordan Thompson (AUS) bt Federico Del Bonis (ARG) 7-6 (8/6), 6-4
Daniel Galan (COL) bt Thiago Wild (BRA) 6-3, 6-4
Bjorn Fratangelo (USA) bt Fernando Verdasco (ESP) 6-4, 6-4
Aljaz Bedene (SLO) bt Thomas Fabbiano (ITA) 7-6 (7/5), 1-6, 6-3
Damir Dzumhur (BIH) bt Kevin Anderson (RSA) 7-6 (8/6), 7-5
Ashleigh Barty (AUS x1) bt Kristina Kucoa (SVK) 6-3, 4-6, 7-5
Jelena Ostapenko (LAT) bt Kirsten Flipkens (BEL) 6-2, 5-7, 6-3
Angelique Kerber (GER x24) bt Renata Zaraza (MEX) 6-0, 6-0
Victoria Azarenka (BLR x14) bt Laura Siegemund (GER) walkover
Belinda Bencic (SUI x11) bt Zarina Diyas (KAZ) 6-2, 6-1
Marketa Vondrousova (CZE x19) bt Wang Qiang (CHN) 6-4, 6-4
Veronika Kudermetova (RUS x32) bt Danielle Collins (USA) 6-3, 6-2
Aryna Sabalenka (BLR x7) bt Tsvetana Pironkova (BUL) 0-6, 6-3, 7-6 (11/9)
Simona Halep (ROM x3) bt Caroline Garcia (FRA) 3-6, 6-4, 6-0
Anastasija Sevastova (LAT) bt Cori Gauff (USA x31) 1-6, 6-2, 6-3
Ana Konjuh (CRO) bt Madison Keys (USA x18) 6-4, 6-2
Iga Swiatek (POL x15) bt Barbora Krejckov (CZE) 6-4, 6-2
Petra Kvitova (CZE x9) bt Alize Cornet (FRA) 6-0, 6-4
Johanna Konta (GBR x17) bt Magda Linette (POL) 6-4, 7-5
Ekaterina Alexandrova (RUS x30) bt Nadia Podoroska (ARG) 6-0, 6-4
Elina Svitolina (UKR x5) bt Shelby Rogers (USA) 3-6, 7-5, 6-3