Serena Williams will continue her quest for Grand Slam glory on Wednesday as the top half contests its quarterfinals. Chris Oddo previews the matchups at wtatennis.com.
 Serena Williams (USA #1) vs.  Simona Halep (ROU #5)
Head-to-head: Williams leads, 7-1
Key Stat: Williams struck a 126 mph serve in her round of 16 match with Yaroslava Shvedova. It is the fastest recorded serve at this year's US Open.
Serena Williams has answered all the questions and then some about her health and form during her first four matches in New York. She has dropped just 20 games and not had her serve broken a single time. After passing Martina Navratilova and Roger Federer on the all-time Grand Slam wins list the 22-time major champion will set her sights upon major title No.23 as the business end of the tournament begins. It starts with a battle with No.5-seeded Simona Halep on Day 10. Halep has won 21 of her last 23 matches and has navigated a very tricky draw to reach the quarterfinals at the US Open for the second consecutive season. Now she must find a way to challenge one of the most daunting, indomitable players to ever step on the Grand Slam stage. Halep says she won't be nervous to face Serena Williams?she has nothing to lose. "I don't have to be afraid or to have emotions because I have nothing to lose," she said on Sunday after defeating Carla Suárez Navarro in straight sets. "It's just a huge challenge for me. Just playing my game; I will try to do that." Williams knows that she'll be up for her stiffest challenge of the fortnight when she faces Halep. The Romanian owns a win against her, which came at the 2014 WTA Finals, but since then Williams has taken three in a row against Halep. Williams says she's just taking it day by day and hoping she can improve with every round. "I just feel like I'm going out there doing what I need to do," she said after cruising past Yaroslava Shvedova, 6-2, 6-3, on Day 8. "I'm not overplaying, I'm not underplaying. I'm just trying to play my way into this tournament."
Pick: Williams in two
Surprise, surprise! A pair of first-time quarterfinalists are set to square off for a spot in the US Open semifinals, as No.10-seeded Karolina Pliskova will meet 18-year-old Ana Konjuh for the first time on Wednesday. For Pliskova, this opportunity has been a long time coming. The hard-serving Czech and her easy power have made waves on the circuit for two years, but she has been thwarted at the Grand Slam level and failed to reach the second week of a major in her first 17 appearances. That has changed in the last few days. Pliskova pummeled Anastasia Pavlyuchenkova to reach the round of 16 on Saturday and on Monday the 24-year-old Czech produced one of the most magical moments of the tournament when she saved a match point to defeat Venus Williams in a third-set tiebreaker. She's just three matches from a Grand Slam title, but Pliskova is not thinking about anything but her next battle. "I know it's still far," she said. "It's closer than it was yesterday, but it's still far." Her opponent is the lowest-ranked and youngest player remaining in the draw, but she's also one of the most dangerous. Anyone who witnesses Ana Konjuh's breathtaking victory over No.4-seeded Agnieszka Radwanska on Monday night can see why she's being touted as a future star. Regularly approaching 120 MPH on serve, and striking with wicked pace from both wings, Konjuh had Radwanska on her back foot all night. Can the Croatian back up her stunning upset with another Top 10 win? Konjuh isn't putting too much pressure on herself. "I'm still young," she said. "I still need to experience things. I'm just trying to focus on each player for the day for the match and just give my best."
Pick: Pliskova in two
By the Numbers:
34 - The age of Serena Williams, who is the oldest player remaining in the draw.
3 - Returning quarterfinalists from 2015 (Serena Williams, Simona Halep, Roberta Vinci).
436 - Pliskova leads the Tour with 436 aces in 53 matches this year.
9 - Of the nine teenagers that started in this year's US Open main draw, Konjuh is the only one remaining.
1993 - The last time that an American woman has failed to reach the U.S Open quarterfinals.