* Turns back fellow Italian Giorgi
* Vinci getting better with age (Adds quotes)
By Julian Linden
NEW YORK, Sept 2 (Reuters) - Roberta Vinci beat her opponent and the rain on Monday to storm into the quarter-finals of the U.S. Open for the second year running.
Vinci needed just over an hour to defeat fellow Italian Camila Giorgi 6-4 6-2, finishing in the nick of a time before a thunderstorm forced a lengthy suspension at Flushing Meadows.
"Of course I was lucky," said Vinci after scampering off the courts before the clouds burst.
Better known as a doubles player, Vinci made light work of her match with Giorgi, who had come through the qualifiers just to get into the main draw.
Giorgi, 21, upset former world number one Caroline Wozniacki to reach the fourth round of a grand slam for the first time but was outgunned by the more experienced Vinci.
"It wasn't my day, I didn't play good," she said.
A veteran professional, Vinci is nine years older than Giorgi and getting better with age.
She is currently ranked 11th in the world in singles and shares the number one ranking in doubles with Sara Errani but it has been a slow climb for the 30-year-old.
She made her grand slam singles debut at the 2001 U.S. Open and before 2011, she had only won one singles match at Flushing Meadows.
She had never made the fourth round in singles at any grand slam event until last year but has now made the last 16 at five of the last six majors.
Vinci has also hit a purple patch in doubles. Before last year she had never appeared in a grand slam final but has played in five since the start of 2011, winning the French Open and U.S. Open in 2012 and the Australian Open in January.
"I know that I'm not young, but I'm enjoy playing," Vinci said.
"I have a high ranking so I'm happy, and I try to stay focused every single day."
Vinci could play another Italian in the quarter-finals if Flavia Pennetta wins her fourth round match against Romania's Simona Halep.
Pennetta, 31, was leading Halep 6-2 4-5 when the weather turned foul and play was halted.
(Reporting by Julian Linden,; editing by Gene Cherry)