Melbourne - The vast experience of Rafael Nadal meets the exciting youth of Stefanos Tsitsipas in a fascinating first men's semi-final at the Australian Open on Thursday.
Tsitsipas, the 20-year-old Greek with all the gifts, pulled off the win of his life to knock out Roger Federer in four sets in the last 16.
The 14th seed Tsitsipas has already etched his name in Greece's sporting pantheon by becoming the first player from his country - man or woman - to reach the semi-final of a Slam.
The NextGen Finals champion with the flowing locks will continue his ascent to Greek god-like status if, aged 20 years 170 days, he becomes the youngest major finalist since Novak Djokovic (20 years, 112 days) at the 2007 US Open.
But first he has to tame the rampaging bull that is the Spanish world number two Nadal, who has blasted through the draw without dropping a set as he chases his own slice of history.
Victory for Nadal in his sixth Australian Open semi-final would keep him on course to be the first man to win all four Grand Slams twice in the Open era.
Tsitsipas lost both of his previous meetings with Nadal, blown away on Barcelona's clay 6-2, 6-1 last year but giving him a tougher examination on a hard court in Canada.
"I felt very close to beating him in Toronto, though the score was 6-2, 7-6," said Tsitsipas.
"I remember coming back to the locker room and promising to myself I'm going to do much better against him next time.
"I feel like I can do something good against him."
Nadal came to Melbourne having not played since the US Open and subsequent foot surgery, but insisting he was fully fit despite pulling out of his Brisbane warm-up.
He also promised to unleash a remodelled, more powerful serve to add a new weapon to his deadly arsenal.
He has been as good as his word, looking fitter, faster and stronger with every match.
And the serve? It is now an astonishing 51 straight games since it was last broken - four matches ago in the third set of the first-round encounter with James Duckworth.
At the age of 32 he has already dismissed the challenge of two NextGen talents.
He shattered the dreams of 19-year-old Alex de Minaur in the third round and then in the quarter-final destroyed 21-year-old Frances Tiafoe, who was left in awe of the 17-time Grand Slam champion.
"I knew if he got hold of a forehand, it was going to be barbecued chicken," admitted American Tiafoe. "Point in, point out, I've never seen someone so locked in."
Nadal is wary of Tsitsipas, who he called "one of the best players in the world", but declared his own time was not yet up.
"They can wait a little bit," said Nadal of the new kids on the block.
"But looks like they don't want to wait. They're here.
"Stefanos is one of the best players of the world. To have the chance to be in that final, I need to play my best, and that's what I am looking for."