In a demanding sport where every player in every tournament loses -- except one -- Coco Gauff is currently that singular exception.

After dispatching Maria Sakkari 6-2, 6-4 in the quarterfinals of the China Open, the 19-year-old American is riding a 16-match win streak.

“It doesn’t feel like 16,” she said afterward. “It kind of went by fast.”

Quarterfinal results

No.17 won’t come easily. Gauff will meet Iga Swiatek in a Saturday collision of the No.2- and No.3-ranked players on the Hologic WTA Tour. They lead all WTA players with seven Top 10 wins this year -- only one will emerge with an eighth.

The other semifinal features No.5 Elena Rybakina against rising star Liudmila Samsonova. That means three of the Top 5 players will take to the Diamond Court at the National Tennis Center in Beijing. Three of them are 22 years old or younger, and Rybakina is only 24. 

No.2 Iga Swiatek vs. No.3 Coco Gauff

The case for Swiatek: She defeated No.9 seed Caroline Garcia in a wild quarterfinal, 6-7 (8), 7-6 (5), 6-1.

It was her 25th victory in WTA 1000 events this year -- one more than last year when she finished No.1. Swiatek has now recorded 61 wins this year, the most of any player, excluding Billie Jean King Cup matches. She is the first player to register consecutive seasons of 60-plus wins since Agnieszka Radwanska in 2012-2013.

China Open: Scores | Schedule | Draws

Swiatek had beaten Gauff seven straight times to open their head-to-head series when they met in the Western & Southern Open semifinals back in mid-August. Gauff won 7-6 (2), 3-6, 6-4.

“I know also how she plays, what she’s improved, what she changed,” Swiatek said. “I’m just going to use that information and not overanalyze because I think we’re both good players. Now we just have to kind of both fight.

“I’m sure it’s not going to be an easy match probably. It’s going to be tight.”

The case for Gauff: She hasn’t lost in 57 days, going back to her defeat in Montreal at the hands of doubles partner Jessica Pegula. She’s won 20 of the past 21 matches, bringing her a WTA 500 (Washington, D.C.), a WTA 1000 (Cincinnati) and a Grand Slam (US Open).

That win in Cincinnati over Swiatek looms large in this one.

“Yeah,” Gauff said. “I have more confidence going in. It’s going to be a tough match. I mean, she's a tough player. I’m not going to try to put too much pressure on myself. I lost to her a lot of times. I’ll try to get number two on the board.”

Gauff saves four set points vs. Kudermetova to make Beijing quarters

How well has she been playing? Gauff has 36 hard-court wins this year, excluding Billie Jean King Cup, the most among WTA players. The last American teenager to win that many in a season was Venus Williams (42) in 1999. The last teenager to get this far in Beijing was Agnes Szavay in 2007.

One more bit of context: Gauff is the first American teenager with a 16-match win streak since Serena Williams in 1999.

No.5 Elena Rybakina vs. Liudmila Samsonova

The case for Rybakina: She just beat Aryna Sabalenka, the No.1 player in the world, 7-5, 6-2.

In a matchup of lethal hard-hitters, Rybakina was better. She ripped 12 aces, against only a single double fault. She’s the first player to win four consecutive matches against reigning No.1s since Belinda Bencic (2015-19).

With Sabalenka serving at 5-all in the first set, Rybakina displayed enormous poise, winning the 20th point of the game, converting her fifth break point. That was the turning point and delivered her into a fifth WTA 1000 semifinal for the season.

A win on Saturday would put her into a fourth WTA 1000 final. Previously, Rybakina won in Indian Wells and Rome and lost to Petra Kvitova in Miami.

In her previous four matches, Samsonova spent 7 hours, 38 minutes on court -- more than any other player in the semifinals.

The case for Samsonova: Like Gauff, the 22-year-old Samsonova comes into this match buoyed by a powerful dose of recency bias.

Back in August, Samsonova reached the final at the WTA 1000 event in Montreal. She beat Sabalenka in the Round of 16 and later Rybakina in the semifinals. Previously, Samsonova defeated Rybakina two years ago in Montreal and last year in Tokyo.

Samsonova handled No.13 seed Jelena Ostapenko 6-3, 6-2 -- in 66 minutes. That win pushes her back into the Top 20, not far below her career-high No.12 ranking back in February.

Tactically, Samsonova said in an interview, Rybakina and Sabalenka offer similar challenges.

“Against Lena, I need to be really, really powerful,” she said. “I’m good, ready to go.”

Samsonova has beaten Rybakina all three times they’ve played.