CHARLESTON, SC, USA - Former World No.1 Caroline Wozniacki sailed into her first WTA semifinal of 2019, dismissing No.15 seed Maria Sakkari, 6-2, 6-2 at the Volvo Car Open.

"I think I've been here in this situation many times, and it's all about just taking it match for match, just really no easy opponents at this point, and you just have to be out there and do your best and hope that that's enough," she said in her post-match press conference.

GALLERY: Great Escapes - WTA stars winning from match point down

Wozniacki has struggled with illness and a recent rheumatoid arthritis diagnosis since the end of last season, but the Dane is sliding into her stride in Charleston, needing 93 minutes and a titanic final game to knock out the Greek star on Volvo Car Stadium.

"Before Indian Wells I only had a few days I was on the court.  I went into Indian Wells basically having not trained for maybe two months since Australia.  So I was just very happy to be able to play on a pretty high level, but I just ran out of steam, out of gas, and I needed like four days to recover after that.

"I just got myself ready on clay, and I'm feeling healthy, which is the main thing, and now it's just all about enjoying being out there."

Sakkari won her only previous encounter with Wozniacki at the 2017 Dongfeng Motor Wuhan Open, and enjoyed a scintillating run into her first quarterfinal of the season after back-to-back wins over 2014 Volvo Car Open winner Andrea Petkovic and defending champion Kiki Bertens.

The 23-year-old nonetheless struggled to find her range on an inclement Friday afternoon against the more experienced Wozniacki, who has included former French Open champion Francesca Schiavone among her coaching team this week.

"I think probably if you look back ten years ago, I was probably playing just as well on the clay that I do now. You look back five years ago, I would say I've stepped it up, I play much better.

"I grew up playing on clay outdoors, so I kind of knew what to do, and I think I just lost kind of that pattern a little bit once we started playing on hardcourts so much, and I think now I'm just starting to realize what I need to do. I can't always do it, but I at least have the right path and I can see what I need to work towards, and when I play that way, I win a lot of matches and I can play at a very high level on this surface."

The No.5 seed took a deceptively quick 4-0 lead to start the match - three of the first four games went to deuce - and though Sakkari clawed back one of the two breaks, Wozniacki secured a solid service hold and broke serve once more to claim the opening set.

Sakkari began the second set with some of that late momentum, breaking to love and consolidating, only to watch the Dane roll off the next five games to find herself serving to stay in the match.

Fighting through a marathon final game that lasted over 15 minutes and 9 deuces, Sakkari saved a first match point with an audacious second serve ace and another with a searing backhand angle. By her fifth match point, Wozniacki proved too strong, provoking one last unforced error to make it over the finish line.

In a clean performance throughout, she struck 15 winners to just eight unforced errors and converted an impressive six break points, allowing just two service holds from Sakkari the entire match.

Up next for the 2018 Australian Open champion is No.16 seed Petra Martic, who scored a solid upset over Dubai Duty Free Tennis Championships winner Belinda Bencic to open play on Volvo Car Stadium.

"It's definitely going to be tough. She's playing well. She's been playing well on this surface and this tournament so far. We practiced earlier this week. She has that big kick. She has a good serve, forehand, likes to run around it, mix it up with the backhand. So I need to be ready from every point."