She jumped to a 4-1 lead in the first set Monday, but Vinci stayed poised and patient. Vinci, who had never played the younger Italian before, started attacking her forehand, and Giorgi's mistakes mounted. She finished with 35 unforced errors to 20 winners.
"The problem wasn't the opponent," Giorgi said. "The problem is that I wasn't myself on court today."
Vinci is one of only two players seeded in the top 10 left in her half of the draw, along with No. 2 Victoria Azarenka.
About two hours after play was halted, the courts had been dried but the players weren't yet warming up. Sure enough, rain started to fall again.
Finally, almost 4 hours after they left the court, the Alison Riske vs. Daniela Hantuchova and Simona Halep vs. Flavia Pennetta matches resumed.
Azarenka's meeting with 13th-seeded Ana Ivanovic was postponed. So was the Williams sisters' doubles match.
Rafael Nadal and Roger Federer were each still scheduled to play later Monday, though there was more rain in the forecast.
Arthur Ashe Stadium is finally getting a roof, the U.S. Tennis Association announced last month. But that won't happen until 2016 at the earliest. For now, rain delays are the reality at Flushing Meadows.
If Nadal and Federer win their fourth-round matches whenever they're actually played they'd meet in a Grand Slam quarterfinal for the first time. The great rivals have met 10 times at major tournaments, but never before the semis.
The potential matchup in the quarters is a byproduct of Federer falling to a seeding of No. 7. His match with 19th-seeded Tommy Robredo was moved to Louis Armstrong Stadium. It would be the first time since the fourth round in 2006 also because of rain that Federer played on the U.S. Open's No. 2 court.
The second-seeded Nadal wasl scheduled to play No. 22-seeded Philipp Kohlschreiber on Ashe to start the night session.