Half of the top 10 seeds in the women's draw are already out of the U.S. Open.
The second day of the tournament started just like the first, with sixth-seeded Lucie Safarova the one getting upset this time. The French Open runner-up had a tough first-round matchup against 37th-ranked Lesia Tsurenko and lost 6-4, 6-1 in just 65 minutes Tuesday.
Seventh-seeded Ana Ivanovic, eighth-seeded Karolina Pliskova and 10th-seeded Carla Suarez Navarro were all eliminated Monday, a day after third-seeded Maria Sharapova withdrew because of a leg injury.
Safarova had defeated Tsurenko in straight sets in New Haven just four days earlier. She went on to lose a three-setter to Petra Kvitova in the title match Saturday.
Tsurenko had been playing well on the hard courts this summer to reach a career-best ranking this week. The 26-year-old from Ukraine upset Pliskova to make the New Haven semis, where she fell to Safarova. Before that, she upset Wimbledon runner-up Garbine Muguruza in advancing to the quarterfinals in Toronto.
The U.S. Open is the only major tournament at which Safarova has never reached the quarterfinals. The Czech lefty took Serena Williams to three sets in the French Open final.
Second-seeded Simona Halep avoided the upset bug Tuesday, moving on in 47 minutes when Marina Erakovic retired in the second set. Halep was leading 6-2, 3-0.
That adds to the seven retirements Monday, which the ITF said matched the Open era record for the most in one day at a major.