NEW YORK, NY, USA - Six-time US Open champion Serena Williams stormed through 10 of the final 13 games of a highly-anticipated quarterfinal clash with fellow former World No.1, 6-4, 6-3, to surge into the semifinals in Flushing Meadows.

"I'd been a couple steps away at the last Grand Slam, so I'm definitely not ahead of myself," Serena said in her post-match press conference. "I still know that no matter whether I'm in the semifinals or the finals, I have a really long way to go to win that. Again, that proved to be true at Wimbledon. I'm just taking it one at a time, literally."

Williams last played Pliskova at this event two years ago, with Pliskova scoring a career-defining win that took her into a maiden Grand Slam final and later the top of the WTA rankings. 

The three-time WTA Ace leader appeared on course for a similar victory to kick off the night session on Arthur Ashe Stadium, leading by an early break before the 23-time Grand Slam champion roared back to secure her first Top 10 win of 2018 after one hour and 23 minutes on court.

"That's a really big step for me. Shocking that it's my first Top 10 win. I really felt like I was playing well in Cincinnati, even though I lost," she added, referencing a narrow Western & Southern Open loss to Petra Kvitova. "I was just on the verge. If I could have just had one more match before I played a Top 10 player, I think I would have done better. I'm getting those matches now. I was just so light on the matches. Now I feel like I'm at a level where I can play and try to compete against these amazing women in the Top 10."

Pliskova nonethess enjoyed a solid start, reading the Williams serve to break first and hold three break points to take a 4-1 lead.

"I just thought that I wasn't playing my best tennis. I was thinking I can play better. So that was the good news. Then I thought to just try making less errors, because at that point I was missing a lot of shots. I just had to figure out a way to just try to at least make one, and one at a time."

Spurred on by the crowd, the American held on and began to find her footing later in the set, putting away a swing volley when the No.8 seed served two points from 5-3 to turn the tables and level the set.

"I had couple break points," Pliskova recalled after the match. "I think that was the biggest chance for the first set because with a double break, I would feel for sure less pressure on my serves. It was a lot of mistakes from both sides in the beginning; I was just a little bit better than she was.

"Somehow I just couldn't find my rhythm at all in the first set, and she found it in the end of the first set, so that was the difference."

Suddenly it was Pliskova against the wall as Williams engineered two set points in the tenth game, converting the second to complete the comeback.

Nearly 20 years removed from her first major title at the US Open, the American took that momentum through the second set, rolling out to a 4-0 lead before Pliskova stepped in to break back. 

Things threatened to swing back Czech-ward as Serena served down 0-40 at 4-2, but saved four break points to restore order and maintain her advantage and serve the match on her 13th ace.

In all, she struck 35 winners to 30 unforced errors, dictating play throughout while Pliskova managed just three aces and 19 unforced errors to 12 winners.

"She's one of the best players in the world," Pliskova said. "Doesn't matter that she's No.17 or No.18 now. I think she's still the strongest. She's not going to give you anything. She's just going to ace you or play the best points on your chances. That's just how it is. But I'm pretty positive about those two weeks what I did here. I felt like I improved in quite lot of things. Obviously was enjoying my time on court, which is for me now the most important."

Standing between Williams and a ninth US Open final is Latvia's Anastasija Sevastova, who avenged her 2017 quarterfinal loss to No.3 seed Sloane Stephens, stunning the defending champion in straight sets earlier in the day.

"I've seen her play a lot. She's been playing really well for actually a long time. So obviously I know her game really well. She clearly knows mine. So she's definitely someone that gets a lot of balls back and something I have to be ready for."