MIAMI -- No.3 Jessica Pegula saved two match points to advance to her seventh WTA 1000 semifinal, defeating No.26 Anastasia Potapova 4-6, 6-3, 7-6(2) at the Miami Open. A semifinalist in Miami last year, Pegula becomes the first American to reach back-to-back final four appearances at Miami since Serena Williams in 2014 and 2015. 

Into her second WTA 1000-level semifinal of the season, Pegula will face reigning Wimbledon champion Elena Rybakina on Thursday. Rybakina is bidding to become the fifth woman to sweep the "Sunshine Double," winning Indian Wells and Miami back-to-back in a single season.

Rybakina drops three games to book semifinal spot in Miami

Pegula holds a 2-0 head-to-head record against Rybakina. Their last meeting came during her title run in Guadalajara in October. Pegula saved three match points to win 2-6, 6-3, 7-6(8).

"I don't mind playing her, at least in the past," Pegula said. "Obviously she's picked up her level since then, so it'll be a tough test, especially after this match, just physically see how I feel. Hopefully I can recover in time. At least I have another day.

"I think she and Sabalenka are the ones to beat right now so it's going to be a great test and a deserved semi for a tournament like this."

Pegula came into Tuesday's match with a 3-0 record against Potapova, but the American was wary of the challenge before her. Their most recent meeting came two weeks ago at Indian Wells, where Potapova had her on the ropes, leading 3-1 in the final set before Pegula mounted a comeback to win.

The start of the match was delayed for nearly four hours because of rain, with the players taking the court at 10:45 p.m. The effect of the lengthy delay was evident from the start of the match, as both players struggled to find their rhythm and intensity from the baseline.

But after falling behind 2-0, Potapova played cleaner, more consistently aggressive tennis to win five straight games and lead 5-2. Pegula closed the gap to 5-4, but she was broken for the set after a Potapova backhand skimmed the back edge of the baseline for a clean winner on set point. 

Pegula responded by halving her unforced error count (19 to 10), improving her first serve percentage (50% to 63%), and going perfect on her break point chances (3 for 3). This time it was Pegula rebounding from a 2-0 deficit, as the American won four consecutive games to build a 4-2 lead and force a decider from there.

Potapova came into the match leading the Hologic WTA Tour in three-set wins with an 8-3 record, and she proved her mettle once again down the stretch. On a night when a 2-0 lead proved precarious, Pegula saw Potapova win four consecutive games to lead by a break at 4-2. 

"Legs were heavy at like 2-0 in the third," Pegula said. "I think I worked so hard to win that second set, and then to go up 2-0 to get the break, it just hit me and I kind of had a lull there for a couple of games."

With Potapova serving for the win at 5-4, Pegula saved two match points at 40-15 and broke on her third break point to level the set. Undeterred, Potapova broke immediately to earn a second chance to serve out the win, but again Pegula broke back, this time to force a deciding tiebreak. 

This time Pegula built a lead she would not relinquish. With her forehand locked in again, Pegula raced out to a 5-1 lead and closed out the win after 2 hours and 36 minutes. The match ended well after 1:00 a.m.

Pegula became the first player to save match points en route to victory in two matches this season; she did so against Jelena Ostapenko during her run to the Doha final in February. 

"She was just playing fearless, just going for her shots, moving well," Pegula said. "The key was to not get too frustrated and just try and stay within one break in the third even though I was really gassed. I knew regardless she would get tight trying to close it out. She got a little tight and I was able to take my chances."