Mother Nature made her presence known at Flushing Meadows on Wednesday. With the weather ranging from extreme heat and humidity to rain, the players were forced to adapt. But at the end of the day, there were tickets into the semifinals for four competitors.

Federer Advances with Ease

In a matchup of two veterans, Roger Federer faced off against Richard Gasquet under the lights of Arthur Ashe Stadium. The 12th seed was no match for the world No. 2, who advanced 6-3, 6-3, 6-1.

Gasquet entered New York playing arguably the best tennis of his career, and early in the first set, he went toe-to-toe with the second seed. But that would not last as Federer was near-perfect on his serve, quickly holding behind a flurry of aces. Meanwhile, he would find a hiccup in the Frenchman’s serve. giving him an opening to take the set.

In the second set, Gasquet would run into trouble with some loose groundstrokes, and Federer would cash in with relative ease. The 17-time major champion received little resistance during a businesslike set. In the third set, Gasquet’s movement appeared to slow as the Swiss continued to construct solid, crisp points from the baseline, as well as crisp volleys. The Frenchman had no answer and appeared defeated prior to the finish line. Federer would close out the match, setting up a semifinal matchup with Stan Wawrinka.

It was one of the better performances from Federer in some time. He concurred and looks forward to meeting his friend. “No doubt about it, I played a very good match. I was feeling the ball great,” Federer said. “I felt like I had extra time on the returns. My serve worked very well. I was able to stay aggressive and enjoy myself out there. It was a great match. Being a quick match, it will help to save energy. I couldn't be happier to play Stan here. Two Swiss guys in the semifinals of the US Open is pretty cool.”

Halep fights through to the semis

Second-seeded Simona Halep met Victoria Azarenka in the afternoon session of Day 10, and it was the Romanian advancing 6-3, 4-6, 6-4.

In the first set, perhaps with nerves surfacing, both players struggled to hold serve. But it was Halep who would adjust first, striking clean, confident groundstrokes to gain the early advantage. And while the Belarusian struggled holding serve, the world No. 2 was steadfast in taking the first set.

But in the second set, a more emotional Azarenka quickly seized control and gained a service break. Although her opponent would even the set, Azarenka’s intensity spiked again, and she would gain an edge once more. However, Halep would not yield the set without a fight, and she gained her own service break. But she could not consolidate it as she attempted to serve to stay in the set, and the match moved to a third set.

With her frustrations visible, Halep waited for Azarenka to return from an extended break between sets. However, when she finally returned, Azarenka was tested but held serve in a competitive 12-minute game. She would follow with a break of service behind deep, strong groundstrokes that would back Halep off the baseline. But it was short-lived as the 23-year old quickly returned the favor.

Then, after the tournament’s first rain delay, Halep returned to the court with a more positive approach after some negativity had crept in during the second set. She was focused and steady the remainder of the match, gaining a break and closing the match out on her serve to advance to her first U. S. Open semifinal.

Halep assessed her performance afterwards, saying “It was a tough match, and at this level, the highest level of tennis, it's normal to play three sets, I guess,” she said. “I'm really happy with the win. I don't know where I found the power to win this match.”

Pennetta upsets Kvitova to advance

In early action in Arthur Ashe Stadium, Flavia Pennetta rallied from a set down and upset fifth-seeded Petra Kvitova 4-6, 6-4, 6-2.

The Czech appeared out of sorts through much of the match, lacking in vigor on many of her shots. Meanwhile, Pennetta would consistently counterpunch and take her chances when available. As the errors piled up for the two-time major champion, Pennetta surged.

In the first set, Kvitova took advantage of her break opportunities, while the 26th seed did not. But that statistic changed as the match progressed. Kvitova aggressively attacked, but unforced errors gave the Italian open doors in the second and third sets. And while Kvitova was successful when she approached the net, she could not consistently offset her 60 unforced errors. Additionally, Pennetta found success against the 25-year-old’s second serve, taking 60 percent of those points.

In the decisive third set with the New York heat bearing down, it appeared that the big hitter had wilted in the hot and humid conditions and was running out of gas. Pennetta would break twice to close out the match.

She sympathized with Kvitova afterwards. “I'm sorry for her,” Pennetta said. “It's not a good feeling when you feel so tired you can't move really well. She played a really tough match, running everywhere. She has to be proud of herself because she's playing until the last point.”

Wawrinka rolls to the Semifinals

Fifth-seeded Stan Wawrinka met a red-hot Kevin Anderson in a match that was moved to Louis Armstrong Stadium due to the weather. And it was complete domination for the Swiss, who got through 6-4, 6-4, 6-0.

It was a battle of big serves early in the opening set as both players were stingy during their service games. But a focused Wawrinka took advantage of a poor service game by the South African midway through. It was the one break he would need.

The second set nearly mirrored the first with Wawrinka managing his service games while measuring Anderson’s big serve and benefiting from errors. That combination gave him enough to close out the set in a straightforward manner.

Playing with an intensity not seen previously during this fortnight, Wawrinka broke serve immediately in the third set. He would proceed to run through the set with Anderson possibly feeling the side effects from his four-hour battle with Andy Murray in the round of 16. Anderson would win just five points in the third set.

Wawrinka did not lose a service game in the match. He was pleased with his performance, saying “For sure, it was the best match of the tournament for me.” He acknowledged that he expects strong support for Federer in their semifinal match. “Everybody loves Roger. He's the best player ever,” Wawrinka admitted.