Zarina Diyas cools off Coco Gauff in first round of Washington D.C.

On a sweltering Tuesday in Washington D.C., fans packed the stands of John Harris Court for the chance to see Cori “Coco” Gauff take on Zarina Diyas in the first round of the Citi Open. Though proceedings looked promising early for the captivating 15-year-old qualifier, Diyas quickly cooled off the American—and the buzz surrounding her—with a 6-4, 6-2 victory.

The first set presented both players with a test of nerves and patience. Gauff twice relinquished a break advantage to Diyas, including at 4-3. Serving to stay in the set, Gauff was pressed once again. She saved three set points with controlled aggression on her serve placement and backhand down the line, and reached game point twice, but Diyas dug in to claim a 10-minute game for a one-set lead.

The bleeding stopped for Gauff when she staved off four break points to hold for 1-1 in the second set. Diyas, to her credit, stayed the course and was undaunted by the pro-American audience. Gauff let a 40-15 lead slip when serving a 2-3, ending a disappointing game with her sixth double fault. Throughout the encounter, Diyas directed her shots to Gauff’s forehand, a strategy that would ultimately pay off in the 79-minute victory.

Diyas finished with a comprehensive 16 winners to eight unforced errors ratio. It’s the second time she's silenced a 15-year-old American sensation, having defeated CiCi Bellis in the second round of the 2014 US Open. The 25-year-old, who avenged her first-round doubles loss to Gauff and Caty McNally, will face fifth seed Lesia Tsurenko for a spot in the quarterfinals.

Gauff had to wait until last week to see if her pre-Wimbledon ranking of No. 313 would gain her entry into the qualifying draw. Including qualifying rounds at Wimbledon and D.C., the now 146th-ranked Gauff had won eight of her nine matches coming in, highlighted by her memorable round of 16 showing at the All-England Club.