The 2015 Citi Open kept chugging along Friday, as some of the world's most prominent names hit the hard-court surfaces in preparation for the U.S. Open.
From quarterfinal bouts between hopeful Americans to international studs vying for spots in the semifinals, there was plenty to take in during an action-packed day in Washington D.C.
Here's what happened in the tournament on Friday and how things are set up for the penultimate day of competition Saturday.
|2015 Citi Open Results - August 7|
|Men's Singles||No. 2 Kei Nishikori||Sam Groth||6-4, 6-4|
|Men's Singles||No. 3 Marin Cilic||Alexander Zverev||7-5, 7-6|
|Men's Singles||No. 8 John Isner||Ricardas Berankis||6-3, 5-7, 6-3|
|Men's Singles||Steve Johnson||No. 15 Jack Sock||7-6, 6-1|
|Women's Singles||No. 1 Ekaterina Makarova||No. 6 Irina Begu||6-4, 2-6, 6-1|
|Women's Singles||No. 2 Samantha Stosur||Monica Niculescu||4-0 (Retired)|
|Women's Singles||Sloane Stephens||Louisa Chirico||6-4, 6-4|
|Women's Singles||Anastasia Pavlyuchenkova||Christina McHale||2-6, 6-1, 7-6|
An updated look at the Citi Open draw can be found at the tournament's official website by clicking here.
Unlike the past few days at the Citi Open, Friday didn't offer much on the upset front. And moving forward, that's a good thing, because it means the few remaining favorites will be taking center stage.
Kei Nishikori dominated Australian Sam Groth in straight sets (6-4, 6-4) to advance to the semifinals, which means the tournament's No. 2 seed is set to do battle with No. 3 seed Marin Cilic.
While Cilic may be a bigger name at this stage in the players' respective careers, Nishikori has been clearing obstacles with aplomb of late.
Friday, Nishikori took down Groth in under 90 minutes, thanks to his efficiency on second-serve points and break points. When all was said and done, Nishikori won 60 percent of the match's second-serve points—16 percent better than Groth. Nishikori also saved all four of his break points, while Groth converted seven of his nine.
"It was my first time playing against Sam," Nishikori said following the win, according to ATPWorldTour.com. "I had to guess on my returns a lot since as hard as he serves, it's tough to see the ball. But I was feeling good on my returns, coming in more than usual and being aggressive."
According to the Associated Press (via Sports Illustrated) Nishikori's 41 wins on the ATP World Tour this year rank second behind Andy Murray and Novak Djokovic. Each of the highly touted stars have racked up 48 wins to this point in their respective seasons.
Cilic, meanwhile, made quick work of Alexander Zverev, downing him, 7-5, 7-6, in straight sets. By virtue of his victory, Cilic will now square off against Nishikori in a rematch of the 2014 U.S. Open final that Cilic won.
According to the Washington Post's Ben Raby, the impending matchup holds historic weight:
"It's great to be back in the semifinals here and to have a chance to play against Kei in the United States," Cilic said, according to ATPWorldTour.com. "For sure it is going to be an exciting and entertaining match. It's a great way to start the summer hard-court season, and I feel that my form is getting better match after match."
John Isner and Steve Johnson will meet in the other men's semifinal after the unranked Johnson upset the 15th-ranked Sock in straight sets that took just over 75 minutes.
Isner—the tournament's No. 8 seed—didn't have the luxury of taking down his opponent in straight sets. Instead, the American had to scrap his way to a three-set victory over Ricardas Berankis of Lithuania.
Isner bookended the match with victorious 6-3 sets, but Berankis stole the second set, 7-5, to temporarily strike fear into his challenger.
On the women's side of the festivities, Samantha Stosur received a gift entering the weekend.
Instead of having to slog through a quarterfinal showdown against Monica Niculescu, the Australian won by virtue of her opponent's retirement after Niculescu went down 0-4 in the first set. According to WTA Insider on Twitter, Niculescu was forced to retire due to a left abdominal strain.
"You could see straight away that something wasn't right with her," Stosur said, according to WTATennis.com. "You could see it in her serve. It's too bad. That's the way it goes sometimes. I hope she'll be back on the court soon."
With the win, Stosur advanced to set up a semifinal clash with Sloane Stephens, who defeated fellow American Louisa Chirico, 6-4, 6-4. Thanks to her triumph, Stephens ensured she'll be competing in the seventh WTA semifinal of her career, per WTATennis.com.
Come Saturday, the intensity should ramp up another notch.
Nishikori will be eyeing revenge against Cilic, with the U.S. Open on the horizon, and Stephens has a chance to build some serious momentum against a highly touted opponent like Stosur.
With confidence-building opportunities abounding, expect fierce competition to reign supreme when semifinal action gets underway from the nation's capital.