No. 4 Elena Rybakina falls to Sorana Cirstea to become the highest-seeded woman out at the US Open

The No. 30-seeded Cirstea won 6-3, 6-7 (6), 6-4 to reach the fourth round in Flushing Meadows for the first time.

Elena Rybakina was knocked out of the U.S. Open by Sorana Cirstea, at No. 4 becoming the highest-seeded women to be eliminated thus far.

Elena Rybakina, of Kazakhstan, reacts during a match against Sorana Cirstea, of Romania (AP)

The No. 30-seeded Cirstea won 6-3, 6-7 (6), 6-4 to reach the fourth round in Flushing Meadows for the first time.

Rybakina was also seeking to reach the last 16 at the U.S. Open for the first time. The 2022 Wimbledon champion from Kazakhstan had high hopes after her strong results on hard courts earlier this year, reaching the Australian Open final, winning the title at Indian Wells and then getting to the final in Miami.

But after getting a walkover in the second round when Ajla Tomljanovic had to withdraw with a knee injury, Rybakina wasn't sharp in her first match since Monday. She committed 56 unforced errors to 30 winners and had her serve broken six times.

Cirstea advanced to face No. 15 Belinda Bencic on Sunday.