When Sloane Stephens trounced Madison Keys in the U.S. Open final two years ago, the two hugged at the net for what seemed like minutes as the new Grand Slam champion consoled her tearful friend.

After Keys turned the tables on her buddy in a tense three-set quarterfinal Friday at the Volvo Car Open, there was no such drama.

Moments after Keys finished off a 7-6 (6), 4-6, 6-2 win over Stephens, Maddie and Sloane were chatting and giggling like they'd just shared popcorn and watched the latest episode of "Game of Thrones."

"She was explaining why she hasn't responded to my Instagram direct messages the last couple of days," Keys explained. "Apparently, she gave it up for Lent. So she wanted me to know why she hasn't been responding."

sloane action.jpg

Sloane Stephens plays Madison Keys at the Volvo Car Open Friday, April 5, 2019, in Charleston. Grace Beahm Alford/Staff

The eighth-seeded Keys' first victory over No. 1 Stephens in four tries put her into the Volvo Car Open semifinals for the second straight year. Keys has been to Charleston seven straight years but has never won the title, losing to Angelique Kerber in the 2015 final.

Keys will face 2016 Olympic gold medalist Monica Puig in the Saturday semifinals, while No. 5 seed Caroline Wozniacki takes on No. 16 seed Petra Martic. Puig dismissed 11th-seeded American Danielle Collins 6-3, 6-2, in Friday's late singles match.

"Monica has obviously had some good upsets and good matches this week," Keys said of Puig, who has knocked off the Nos. 13, 3 and 11 seeds this week. Keys is 2-2 in her career against Puig, winning their last meeting on red clay at the 2016 French Open.

The stakes weren't as high Friday as when Stephens whipped Keys 6-3, 6-0 in just 61 minutes in the U.S. Open final two years ago or when Sloane won in the French Open semifinals last year.

But the level of play was certainly high, as the two exchanged racket fire for 2 hours and 12 minutes before an enthralled stadium court crowd.

tight keys.jpg

Madison Keys plays Sloane Stephens at the Volvo Car Open Friday, April 5, 2019, in Charleston. Grace Beahm Alford/Staff

The key break came in the seventh game of the third set, with Keys up 4-2. Stephens screamed in frustration after a long backhand gave her rival two break points; Keys cashed in the second for 5-2, then served out the match.

The match was notable for its intensity and for its lack of line-call disputes, noisy sound effects or shouts of "C'mon!"

"It's always hard to play a friend," said Keys, who has known Stephens since junior tennis. "So you are obviously not going be saying 'Come on!' or in each other's faces or anything like that. We've been friends forever, so if she circles a mark and says it's out, I'm going to believe her."

Martic vs. Wozniacki

Coming into the Volvo Car Open, there seemed little reason to make Martic one of the favorites to take the title.

The 28-year-old Croatian was seeded No. 16 but had played in Charleston only once before (losing in the first round way back in 2011) and had a 3-4 match record this season prior to arriving on Daniel Island.

But after Martic made the second round on hard courts in Miami last week, her coach, Sandra Zaniewska, had a feeling.

"She just kept on saying, 'OK, you are going to rule the clay courts,'" Martic said Friday. "And I was laughing about it. But I was like, she made a point up there."

Martic action.jpg

Petra Martic of Croatia earned a spot in the Volvo Car Open semifinals. Grace Beahm Alford/Staff

The coach's point is becoming clear, as Martic became the first player into the Volvo Car Open semifinals with a 6-3, 6-4 win over No. 9 seed Belinda Bencic.

Wozniacki, a 2011 champion in Charleston, will face Martic in the semis after a 6-2, 6-2 win over No. 15 seed Maria Sakkari of Greece. Martic is 0-5 in her career against Wozniacki.

The score against Sakkari looked routine, but Wozniacki — a marathon runner of note — had to sweat out five match points and a 16-minute, nine-deuce game to finally close out Sakkari, who doubled her 2019 win total by reaching the quarterfinals here.

"It took a long time," said Wozniacki, a 28-year-old from Denmark. "Some great shots from both of us ... She made drop shots, she made every first serve. And when she had game point, I came up with some crazy shots, too."

woz jube.jpg

Caroline Wozniacki plays Maria Sakkari at the Volvo Car Open Friday, April 5, 2019, in Charleston. Wozniacki won in straight sets (6-2,6-2). Grace Beahm Alford/Staff

Wozniacki has won 30 WTA Tour titles and was ranked No. 1 in 2010. But this is the first WTA Tour Premier level semifinal for Martic, who is 4-0 this week and ranked No. 53. In her career, Martic has reached the round of 16 in four Grand Slam events, including the French Open clay and the grass of Wimbledon.

"The fact that I played well last year on hard courts and I made the fourth round at Wimbledon on grass, which was quite surprising for me, to be honest," Martic said. "It gave me confidence and belief that I can actually play well on all surfaces."

Emma's week

Also Friday, Charleston teenager Emma Navarro saw her Volvo Car Open run come to an end.

The Ashley Hall junior and her doubles teammate, Chloe Beck, lost to Lucie Hradecka and Andreja Kelpac 6-3, 6-2, in the second round of the doubles draw.

Navarro and Beck defeated 2017 French Open champ Jelena Ostapenko and her partner Darija Jurak 1-6, 6-3 (13-11) in the first round. In singles, Navarro lost to Germany's Laura Siegemund on Monday night.

Making a difference

Madison Keys was late to a dinner in her honor at The Dewberry Hotel on Friday night (she had a good reason) but was proud to receive an award as a Player Who Makes a Difference from the Volvo Car Open.

Keys' "FearlesslyGIRL" non-profit works against bullying and has hosted summits in Illinois, Miami and New York. Shelby Rogers received the award last year.

"(The tournament) giving me an award and donating to the charity means a lot, because it's something I believe in tremendously," Keys said. "And to have more and more people believing in it just means a lot to me."

Friday on Stadium Court

Petra Martic def. Belinda Bencic 6-3, 6-4

Caroline Wozniacki def. Maria Sakkari 6-2, 6-2

Madison Keys def. Sloane Stephens 7-6 (6), 4-6, 6-2

Monica Puig def. Danielle Collins 6-2, 6-2

Reach Jeff Hartsell at 843-937-5596. Follow on Twitter @Jeff_fromthePC

We're improving out commenting experience.

We’ve temporarily removed comments from articles while we work on a new and better commenting experience. In the meantime, subscribers are encouraged to join the conversation at our Post and Courier Subscribers group on Facebook.