CHARLESTON, SC, USA - Nearly an hour after her first two match points came and went, No.7 seed Madison Keys nonetheless earned a 6-2, 6-7(5), 7-5 victory over compatriot Bernarda Pera to return to the semfinals at the Volvo Car Open on Friday afternoon.

Keys took the long road to victory as she held two match points on Pera's serve in the 12th game of the second set, but the World No.101 held on to not only save both chances and come from a mini-break down to win the ensuing tiebreak, but move ahead by a break in the decider. 

However, it was the 2015 runner-up who had the final say in the two hour, 14-minute encounter, as she won five of the last six games of the match to make the final four in Charleston for a second time.

"She played really, really well in the second and third sets. It was definitely tough to bounce back after having match points in the second set, but I was happy I was able to do it," Keys said on-court after the match. 

"I think the biggest thing was going for my shots and not letting her dictate everything. I always feel the crowd support when I'm out here, and I definitely appreciate it."

Keys struck 30 winners over the course of the match, ending with a positive differential to her unforced errors as she misfired 28 times.

Though she ended the match with just three aces, the American did not face a break point over the first two sets and won 72 percent of the points played behind her first serve overall.

"It's always tough when you have match points and they're not there all of a sudden," she added after the match. "I think matches like this are really great, because you have to figure things out and you have to get through tough moments."

For the uheralded Pera, whose 2018 has already seen her reach the third round of the Australian Open as a lucky loser, the end of this tournament will mark a new milestone in her career: the 23-year-old will crack the world's Top 100 for the first time. 

"Overall, I think it was a good week for me. I think Madison played great. In the first set, the court seemed so small because I've never played on a stadium this big," Pera said. "It took me a little to get used to all the people and how big the stadium is.

"I'm a little relieved that I finally cracked Top 100, but I knew I was going to do it, so I have to set new goals now. Before the tournament if somebody said, 'You'll lose to Madison in the quarters, 7-5 in the third, I'd say I'll take it. Right now, it's just that I had my chances and I feel like I didn't do enough."

Keys was impressed by the level shown by her compatriot, despite a difference of over 80 places in the rankings between them coming into the match.

"I wasn't really surprised at anything. I knew she was a pretty solid player. She's obviously had some big wins, so I wasn't surprised to see her playing well," the World No.14 said. "I felt like from the second set until about 4-4 in the third, she wasn't making many mistakes, and everything was from the baseline, hard, flat.

"It was really just kind of weathering the storm and trying to stay in it, and I have no doubt that she'll be doing better and better."

Next up for the 2017 US Open finalist who seeks her second championship appearance in Charleston will be the winner of the match between No.12 seed Kiki Bertens and No.14 seed Alizé Cornet.

"The last two have been more of the power players, but obviously my first round was against more of a claycourter [against Lara Arruabarrena]," Keys assessed. 

"I think I'm prepared for it either way. Honestly, I don'r know who's going to win the match. I have no idea. They're obviously two very different players, though. Kiki is going to be similar to today, fighting off shots and just waiting for opportunities, whereas, if it's Alizè, then it's a totally different match, I have to dictate and be ready for pretty much anything that's going to come at me."