New York, USA: Gael Monfils faces world number one Novak Djokovic on Friday for a place in the US Open final determined to shed his image as the court jester of tennis.
The 30-year-old Frenchman is regarded as the sport's most enthusiastic showman, happily hurling himself to the left or right to retrieve a ball.
Already this tournament, he has shown off his repertoire of eccentricities from colliding with a court side clock which came close to falling on top of him to celebrating his birthday by playing a game of 'boules' on rain-lashed practice courts.
Win or lose Friday -- and with a career record of 0-12 against Djokovic, the latter seems more likely -- Monfils insists that enjoying himself on court will always remain key.
"I play tennis because I have fun. I play tennis because I love the sport. If not, I won't wake up every morning and train, because most of people think that jumping or do the trick shot is gifted," said the 10th seed.
"Yes, it's gifted, but is also a lot of work. I won't say I work on the trick shot, but it's like I think physically I'm one of the best.
"And to do that is because you're in a great shape. If I don't have funny I stop playing tennis, for sure."
But there is also unfinished business for Monfils on Friday at Flushing Meadows.
Two years ago, he led Roger Federer by two sets to love and held two match points before he allowed the Swiss legend to fight back and win an epic quarter-final.
When he made his debut at the US Open in 2005, Djokovic was his first round opponent and the Serb overcame cramps and shoulder pain to win in five sets.
Nishikori faces Wawrinka
Djokovic has been on top ever since, including a straight sets win in New York in the 2010 quarter-finals.
Two-time US Open champion Djokovic, chasing a third major of the season and 13th overall, remains wary of the dangers posed by Monfils whose only other appearance in a Slam semi-final was at the 2008 French Open.
"Gael's one of the few players that I will definitely pay a ticket to watch," said Djokovic, playing in a 10th successive semi-final at the US Open.
"He seems more focused at this time of his career and I am definitely expecting a tough battle."
Monfils is enjoying one of the best spells of his career, winning the title in Washington and making the semi-finals at the Toronto Masters where again he lost to Djokovic.
Djokovic should be the fresher having completed just two full matches in five rounds.
He was handed a walkover into round three and was then the beneficiary of two injury-hit retirements.
All of which means the Serb has spent just 4 hours and 34 minutes on court; Monfils has been out there four minutes short of 12 hours.
Friday's other semi-final sees Japanese sixth seed Kei Nishikori face former Australian and French Open champion Stan Wawrinka.
Nishikori reached the semi-final -- his first at any Slam since he finished runner-up in New York in 2014 -- with an impressive five-set triumph over world number two and 2012 champion Andy Murray.
It was just his second win in nine matches with the Briton but he is happy chasing down deficits.
Against Wawrinka, he trails 3-2 but won their last meeting in the Toronto semi-finals this summer.
He also beat the 31-year-old in five sets in the quarter-finals of the US Open in 2014.
Third seed Wawrinka has had a roller-coaster run to the semi-finals.
In his first five rounds he did not face an opponent inside the top 45 while he had to save a match point to beat Britain's Dan Evans in the third round.
"It's going to be interesting for sure against Kei," said Wawrinka, the late bloomer of the men's tour who only reached his first quarter-final of a Slam at the 23rd attempt in the 2010 US Open.