CoCo Vandeweghe Beats No. 1 Karolina Pliskova to Reach U.S. Open Semifinals

CoCo Vandeweghe joins fellow Americans Venus Williams and Sloane Stephens in the US Open semifinals.

NEW YORK – Another American woman is into the 2017 U.S. Open semifinals.

No. 20-seed CoCo Vandeweghe ousted World No. 1 Karolina Pliskova in the quarterfinals on Wednesday, winning 7-6(4), 6-3 to advance to her second major semifinal and second this year.

In the opening set, Pliskova had a slight advantage over Vandeweghe and almost came back from a break down to take the set. But in the 10th game, Vandeweghe saved a set point to hold for 5-5 and then forced a tiebreak, which she went on to win 7-6(4). Pliskova threw her racket in frustration after losing the first set tiebreak.

Pliskova racquet smash: 7/10 #usopen pic.twitter.com/piulAQkLk6

— (((𝙰𝚌𝚝𝚞𝚊𝚕 𝙷𝚞𝚖𝚊𝚗™))) (@lynnlovestennis) September 6, 2017

Vandeweghe & fans on 🔥🔥🔥 after the 1st set vs. Pliskova.https://t.co/yMOLZLzvkQ #usopen pic.twitter.com/HeKWipVUl0

— US Open Tennis (@usopen) September 6, 2017

In the second set, Vandeweghe continued to frustrate Pliskova by staying patient in the points and breaking her serve in the fourth and sixth games. 

The pair had split their previous meetings with two wins apiece, with the most recent match coming earlier this year on clay in Stuttgart, where Pliskova prevailed in straight sets. Like their 2017 U.S. Open quarterfinal match, Pliskova and Vandeweghe's three previous matches before Wednesday all featured a first set tiebreak.

Match Point Moment: @CoCoVandey
- d. No.1 player in the world, KaPliskova ✅
- reaches US Open SFs ✅https://t.co/9RmfubpzZn#usopen pic.twitter.com/d4kXamZWDg

— US Open Tennis (@usopen) September 6, 2017

Pliskova needed to advance to the final in order to hold onto her No. 1 ranking. With her loss in the quarterfinals, Garbine Muguruza will become the new WTA World No.1 on Monday, Sept. 11 after the U.S. Open concludes. Vandeweghe, who will face the winner of Wednesday night's match between Madison Keys and Kaia Kanepi, is expected to rise to a career-best ranking after the U.S. Open.

Vandeweghe joins fellow American women Venus Williams and Sloane Stephens in the semifinals. If Keys advances, four Americans will be in the U.S. Open semifinals for the first time since 1981. After the match, Vandeweghe was asked about the possiblity of two all-American semifinals matches.

"Let's make it four!" she said with a smile to the Arthur Ashe stadium crowd.