Late-bloomer Lorenzi next up for Murray

Youthful visions of Grand Slam titles and the world number one ranking haven't materialized for Paolo Lorenzi, but 13 years of persistence are yielding the best season of the 34-year-old Italian's career.

Lorenzi became the oldest first-time winner on the ATP tour with his triumph at Kitzbuehel in July.

Now at the US Open he's through to the third round of a Grand Slam for the first time.

Lorenzi arrived at Flushing Meadows 2-21 in Grand Slam tournaments.

He's doubled his number of major match wins with a brisk first-round victory over Argentina's Carlos Berlocq and a five-set second-round victory over 30th-seeded Frenchman Gilles Simon.

Lorenzi was cramping so badly at the end of the near-five-hour marathon against Simon that he could barely walk to the net to shake hands.

But the challenges only get bigger, and he next faces world number two Andy Murray, who claimed his third Grand Slam title at Wimbledon before an Olympic singles triumph in Rio.

Their paths have crossed only once before, when Murray rallied for a 3-6, 6-0, 6-2 win over Lorenzi in the round of 32 at Adelaide 10 years ago.

In the intervening decade Lorenzi has continued to toil on the edges of the mainstream.

He's won 357 Challenger matches and 65 ATP level matches.

His win in Kitzbuehel was enough to earn him a place on Italy's team for the Olympics, where he lost in the second round.

Then it was back to a Challenger tournament in Italy before he lost his opener at the ATP tournament in Winston-Salem, his last tuneup before the US Open.

The late-bloomer from Siena, who started playing tennis at the age of seven when he was introduced to the game by his older brother, doesn't mind flying under the radar.

In a season in which the ATP tour is touting its "NextGen" stars -- the 21-and-under players reckoned likely to challenge the hegemony of Novak Djokovic, Murray, Roger Federer and Rafael Nadal -- he's happy to have one title under his belt and to still be improving.

"I?m changing a lot," he said in Kitzbuehel. "We're working every day to try and do something more. I need to improve a lot of things, so this is just the start."