A rollercoaster win for Jelena Ostapenko, an emotional comeback from Ana Konjuh and an unlikely recovery for Sara Sorribes Tormo were all highlights of Day 2 at the Miami Open.

Ostapenko led Wang Xiyu by a set and 3-1, but needed to take the scenic route to eventually get past the Chinese teenager 6-4, 6-7(4), 6-1 in two hours and 12 minutes. Wildcard Konjuh, who has undergone four elbow surgeries in her career so far, scored her first WTA main draw win since Brisbane 2018 over erstwhile junior rival Katerina Siniakova 7-6(3), 7-5. And Guadalajara champion Sorribes Tormo stared down two match points and overturned a 1-5 final-set deficit to defeat Bernarda Pera for the second time this year 6-2, 2-6, 7-5.

Interview: After four surgeries, Konjuh ready to reach full potential

Former Roland Garros champion Ostapenko served notice that her match might be a wild ride in her very first service game, which she held despite serving five double faults. (The Latvian had previously held despite seven double faults in her opening service game against Alison Riske at the 2019 US Open.) But matters were straightforward for the next set-and-a-half. Ostapenko advanced to a 6-4, 3-1 lead, two points from the double break and striking winners from every corner with aplomb.

The cascade of errors that followed was abrupt even by Ostapenko's hot-and-cold standards, and Wang was quick to capitalise. Unleashing on her own forehand, the 19-year-old wildcard reeled off four straight games. Despite another brief purple patch from Ostapenko to force a tiebreak from 3-5 down, Wang held her nerve therein - helped by another pair of double faults from her opponent - to take the match to three.

Despite Ostapenko's audible frustration at losing the second set, the World No.54 rectified her wayward approach in style. It took her six break points to capture the Wang serve for a 2-0 lead, but from there on in Ostapenko's focus did not waver. Another bombardment of winners followed to take her total to 42, and the 2018 Miami runner-up's ambitions of another run to the final remain alive.

"It was important to win this match and to manage after losing the second set very close," said Ostapenko. "I mean, she played really well. I felt she was not missing any balls and playing really aggressive."

Konjuh, whose fourth and most recent surgery in 2019 was an ulnar ligament reconstruction, has found herself sidelined while her Class of 1997 peers Ostapenko, Naomi Osaka, Belinda Bencic and Daria Kasatkina have racked up Grand Slam titles and Top 10 rankings. But the Croat backed up her belief that she can still fulfil her potential with some electrifying tennis against Siniakova.

In both sets, Konjuh had to overturn deficits. She was down 0-3 in the first, and 2-5 in the second - but saved her best tennis to snatch each from behind. All of the five aces she served in the first set came after she trailed 5-6, including three in the tiebreak. And Konjuh would rattle off the last five straight games of the match in majestic fashion, repeatedly finding the lines with powerful winners.

2021 Miami Highlights: Konjuh comeback tallies first win over Siniakova

"I know every game [in the first set] was going to deuce, and she was just playing really well," said Konjuh. "I knew she was going to give me a chance at one point so I just kept pushing. In the second set it was my fault that I was down 2-5 - I made a few double faults. I knew that if I found my level and didn't make mistakes I could come back."

The result means Konjuh remains unbeaten against Siniakova at every level, having defeated the Czech three times in juniors and now twice as a pro. The head-to-head was a confidence boost.

"I remember we played the Australian Open junior finals in 2013, yes" said Konjuh afterwards. "We've played each other a few times over the years so I know what her strengths and weaknesses are, and I took advantage of them today. I think I played a really good match compared to what I've played before, so I'm really happy to be back."

Elsewhere, Sorribes Tormo continued a stellar season that has seen her win her maiden WTA Tour title in Guadalajara two weeks ago, as well as triumphing in two of the six longest matches of the year so far. One of those was a three-hour, 23-minute 5-7, 6-3, 6-4 marathon over Pera in the second round of Abu Dhabi. At two hours and 41 minutes, her Miami victory was a sprint in comparison, but no less dramatic for that.

Sorribes Tormo trailed 1-5 in the third set, and faced match points at 3-5 and 4-5. Pera netted a volley putaway on the first and missed a return on the second as Sorribes Tormo took the last six games of the match, closing out her own third match point with a surprise serve-and-volley attack.

The World No.58's 2021 record is now 12-4, and she has become the first player to win from match point down twice this season. Previously, Sorribes Tormo also saved two match points to defeat Liudmila Samsonova 6-7(6), 6-1, 7-6(4) in the first round of the Phillip Island Trophy.

"I just remember one match point - it was a really tough match," said Sorribes Tormo afterwards. "The score wasn't real - either 5-1 for her in the third set or 6-2 for me in the first. It was really closer [than that]. I just stayed and kept fighting, thinking that I could win and change the score."

Ominously for her opponents, the 24-year-old has been relishing her extended battles.

"I'm happy, I really like to play those matches," she said. "That's what we practice for. I really like to compete. Hopefully many more for me!"

Danielle Collins, a semifinalist in Miami in 2018, was another impressive opening-round victor, striking 27 winners to oust Kristina Mladenovic 6-3, 6-3.