BEIJING -- US Open champion Coco Gauff came back from the brink to defeat Croatia's Petra Martic 7-5, 5-7, 7-6(2) and advance to the Round of 16 at the China Open. Martic served for the win in the final set, but the resilient World No.3 fought back to notch her 14th consecutive victory. 

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Gauff will face either Tokyo champion Veronika Kudermetova or Lesia Tsurenko next.

"Today the struggle for me was honestly holding serve," Gauff said. "I started off serving well in the first set. I think she started to be more aggressive with the return, so it made me second-guess myself.

"But overall I'm happy with today, it was a mental victory, and happy I was able to get through." 

Gauff entered the match with a 1-0 record against Martic, with that win coming in three sets at 2021 Adelaide. Tuesday's duel struck a similar chord, as the duo worked each other around the court over the course of the 3-hour and 1-minute match. The opening set went along with the server before Gauff earned the first break point of the match and converted.

Martic struck back in the second set by consistently testing Gauff at the net. Using her full arsenal of spins, slices and drop shots, Martic refused to give Gauff consistent rhythm. While the first set saw just one break point, Gauff and Martic combined for seven breaks of serve in the second set. After breaking Gauff for a fourth time to lead 6-5, Martic served out the set to take it to a decider.

Martic looked poised to ride her momentum to victory in the final set. With Gauff settling in to a more reactive, defensive position, Martic began to pick apart the American with her pin-point forehands into the corners. Martic earned a chance to serve for her fifth career Top 5 win after breaking Gauff for a 5-4 lead. But Gauff responded with a lung-busting effort to outduel Martic and break to 5-5.

"I don't know how long the longest point was, but I was just telling myself to keep suffering, it will be over in a couple seconds or maybe more than a couple seconds," Gauff said. That's just like a mental thing." 

Buoyed by her comeback, Gauff raced through the decisive tiebreak to seal the win. 

No.4 Jessica Pegula joined Gauff in the Round of 16 by coming back from a set down to defeat Anna Blinkova 6-7(2), 6-2, 6-1 in her opening round. A finalist in Tokyo on Saturday, Pegula overcame a slow start to dominate Blinkova and earn her first career win in Beijing. 

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Despite serving at just 43 percent in the opening set, Pegula earned four set points on Blinkova's serve at 5-4 but failed to break. Blinkova stormed back to take the 59-minute set in the tiebreak, but Pegula's cumulative return pressure paid in the second and third sets. The American generated a total of 19 break points in the match, while facing just four on her own serve. 

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Pegula's win sets up an intriguing Round of 16 matchup with 13th seed Jelena Ostapenko. Pegula owns a 3-1 record against the Latvian, having won their last two meetings. 

In their only match this year, Pegula saved two match points to win 2-6, 6-2, 7-5 in the Doha Round of 16.