Roberta Vinci reached the US Open quarter-finals for the second year in a row with a 6-4 6-2 victory over over her fellow Italian Camila Giorgi.
Vinci needed just over an hour to see off qualifier Giorgi, who had beaten former World No 1 Caroline Wozniacki in the previous round.
And the 10th seed completed her victory moments before it started pouring with rain at Flushing Meadows and play was suspended for more than four hours.
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September 3, 2013 12:00am
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Vinci recovered from 1-4 down in the first set to race away with 11 of the next 13 games against the World No 136.
The 21-year-old Giorgi could not repeat the form she showed against Wozniacki, serving seven double faults and making 35 unforced errors.
Vinci said: "Camila played flat but I served really well and won lots of points that way.
"Camila is a great player and had nothing to lose after winning three matches in qualifying and three in the main draw. She is one for the future.
"I had lots of points to defend, so I am happy to get to the quarter-finals again."
Giorgi said: "It wasn't my day, I didn't play good. It was a great week coming back from two months without playing and I played at a really good level."
"In every match, I give my heart. Maybe the tennis isn't always the best but I know I am trying my hardest every point."
In the quarter-finals, Vinci will play another fellow Italian in the form of the unseeded Flavia Pennetta, who defeated Simona Halep 6-2 7-6.
Slovakia's Daniela Hantuchova returned to the last eight of the US Open for the first time in 11 years with a 6-3 5-7 6-2 success against American wildcard Alison Riske.
"It means a lot to me to be in another quarter-final in New York," said Hantuchova. "In every match, I give my heart. Maybe the tennis isn't always the best but I know I am trying my hardest every point."
Hantuchova must wait to learn the identity of her next opponent as the final fourth-round match in the women's singles between second seed Victoria Azarenka and 13th seed Ana Ivanovic was postponed until Tuesday due to the rain delay.