NEW YORK, NY, USA -- No.3 seeds Nicole Melichar of the United States and Xu Yifan of China moved into the US Open women's doubles quarterfinals on Friday, as they ousted American teenagers Coco Gauff and Caty McNally in two tough sets, 7-6(4), 7-6(2).

Melichar and Xu became regular partners at the start of this season, and the dividends have paid off immediately, as they won the Adelaide title in January and reached the Western & Southern Open final last week. Their strong form continues at the US Open, notching their second win of the week with a one-hour and 40-minute victory over the rising teens.

The third seeds converted both of the break points they held on the day; Gauff and McNally, meanwhile, also broke twice, but let five additional break points go begging during the clash, failing to avoid the tiebreaks which did not go their way.

It was the teenagers who claimed the first big lead, as they took advantage of miscues by their seeded opponents to break Melichar for 4-2. The No.3 seeds, however, struck back in the very next game, with Melichar firing a forehand winner to claim the game on Gauff’s serve. Xu then had to fend off a break point in the following game, but they held on via brilliant Melichar volleys.

The teams advanced to the first-set tiebreak, where the deft touch by Xu and the powerful net play by Melichar kept them level until an untimely double fault by Gauff put the seeds up a minibreak at 5-4. Melichar seized the opportunity, with good serves forcing awry returns from each of the younger Americans, giving the Western & Southern Open finalists a one-set lead.

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An exchange of breaks started the second set, but after that, it was only Gauff and McNally who had chances to break open the set, with a break point on Xu’s serve at 3-3 and two more on Melichar’s serve at 4-4. Again, the seeds stayed sturdy in the forecourt to erase those chances, and they held firm as another tiebreak inexorably came to pass.

The second-set breaker was more straightforward than the first, as Melichar took control at the net with superb volleys, leading her and Xu to five match points at 6-1. Not to be outdone, Xu finished off the match with an error-forcing volley of her own on the pair’s second match point.

Vera Zvonareva and Laura Siegemund devise a strategy during their second-round win.

Photo by USTA

Melichar and Xu are the only seeded team to reach the quarterfinals thus far, as other teams in the favorites column fell by the wayside on Friday.

Earlier in the day, Germany's Laura Siegemund and Russia's Vera Zvonareva upset No.7 seeds Victoria Azarenka of Belarus and Sofia Kenin of the United States, 7-6(4), 6-3.

Siegemund and Zvonareva claimed the 96-minute victory by converting five of their six break points. Last year's women's doubles finalist Azarenka (with Ashleigh Barty) and Kenin held a whopping 14 break points in the tilt, but could only convert four of those.

An opening set that featured six breaks of serve overall was evened at 3-3 when Azarenka slammed a backhand winner down the line, but the Belarusian misfired into the net on break point in the next game to cede the break lead back to her opponents.

However, in the next game, which Siegemund opened with a divine forehand crosscourt winner, the German misfired on her own backhand into the net to tie up the set once again at 4-4.

Azarenka dropped serve at 5-5, giving Siegemund a chance to serve out the set, but the German double faulted to allow the Belarusian-American pair into a tiebreak. In the breaker, Zvonareva gave her squad an early 4-2 lead with a powerful overhead winner, and they eased to the one-set lead, wrapping it up with a putaway by Siegemund.

After another early exchange of breaks started off the second set, Siegemund and Zvonareva took command with a break for 5-3, attained with another searing backhand winner down the line by the German. Zvonareva closed out the match on serve with no fuss, and the German-Russian duo claimed the upset to book a quarterfinal spot.

The all-Russian pairing of Anna Blinkova and Veronika Kudermetova also claimed an upset of a seeded tandem, as they outlasted No.8 seeds Anna-Lena Friedsam of Germany and Katerina Siniakova of the Czech Republic, 6-3, 3-6, 6-1.

The all-American duo of Asia Muhammad and Taylor Townsend were another pair who moved into the quarterfinals on Friday, after they ousted Lucie Hradecka of the Czech Republic and Andreja Klepac of Slovenia, 6-3, 6-7(6), 6-0.

The USTA announced Saturday that it was removing Kristina Mladenovic, and her partner Timea Babos, from the doubles draw, saying it was “obligated to adhere to government guidance” related to Covid-19 precautions. In a statement, the USTA said: "Public health officials of Nassau County, N.Y., have issued quarantine notices for all individuals who had prolonged close contact to a person who previously tested positive for the COVID-19 coronavirus. Kristina Mladenovic is one of these individuals."

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