NEW YORK, ⁠Sept 1 (Reuters) - French showman Gael Monfils celebrated his 40th birthday ⁠with a 2-6 6-1 6-2 6-0 win over Adolfo Daniel ‌Vallejo to reach the second round of the U.S. Open on Tuesday, keeping his farewell Grand Slam campaign alive.

A day after fellow veteran Stan Wawrinka played the ​final Grand Slam match of his career, Monfils ⁠showed he was not ⁠ready to follow him out the door yet, drawing huge applause from ⁠fans ‌on Louis Armstrong Stadium as he fought back from a slow start.

Monfils also became the oldest player to win ⁠a main-draw singles match at Flushing Meadows since Jimmy ​Connors defeated Jaime ‌Oncins on his 40th birthday in 1992.

There was no cake ⁠on court, but ​Monfils received a rendition of "Happy Birthday" midway through his speech.

"That was very special. Playing on my 40th birthday ... you guys made it incredible," Monfils ⁠said.

"You guys made it electric, the atmosphere ​was unbelievable. I tried to put on a great show for you."

A New York semi-finalist in 2016, Monfils produced an erratic display to drop ⁠the first set but roared back in the second to level the match.

Monfils dominated the third set and fired a crosscourt forehand winner to clinch it, as fans rose to their feet in anticipation ​of yet another electrifying win from the ⁠former world number six.

Paraguayan Vallejo freely surrendered breaks in the fourth set ​and wild card Monfils fed off the ‌crowd's energy to secure the victory ​with a big ace to set up a meeting with American Learner Tien.

(Reporting by Shrivathsa Sridhar; Editing by Peter Rutherford)