It will be number one versus number two in the US Open men's final on Sunday, a seismic grand slam title match between Novak Djokovic and Roger Federer that transcends the world rankings.
Both players burn with heaps of motivation to hoist the winner's trophy at Arthur Ashe Stadium in the last grand moment of the 2015 slam season.
Second seed Federer, who won five consecutive US Open titles from 2004 and was runner-up in 2009, reigns on top of the all-time list for grand slam titles with 17.
At the advanced age of 34 the Swiss is playing great and glowing with a desire to win his first grand slam title since his triumph at Wimbledon in 2012.
Djokovic has ascended to the clear number one, but is not number one in the hearts of the New York fans. That distinction rests with the Swiss, who is still the darling of Flushing Meadows, while the Serb longs to be loved.
The 28-year-old Djokovic is gunning for his third grand slam title of the year, which would replicate the dominance of his 2011 season.
Both players have had brilliant years. Djokovic has compiled a 56-5 season with six titles. Federer is 45-7 and won five times. Their career head-to-head is 21-20 in Federer's favor.
Djokovic, the reigning Australian Open and Wimbledon champion, has won nine slam singles and will be playing in his sixth Flushing Meadows final.
But Djokovic has won just one US title (2011) from his five previous finals and the pressure is mounting to cash in on opportunity.
“I came here with a wish and a mission, to reach the finals and fight for the trophy,” said Djokovic. “So I got myself in that position. It's already a great result. But I want to get that final step on Sunday and get my hands on that trophy.”
Their personal series further promotes the likelihood of a pitched battle at Arthur Ashe Stadium, with Federer's victory over Djokovic in the final of last month’s Cincinnati hardcourt tune-up to the US Open edging him ahead in their series.
But Federer has a deeper wound to avenge, having lost in the 2015 Wimbledon final to the Serb.
"I didn't quite agree that I played a poor finals," he said about their clash at the All England Club. "I think I played OK in the finals," he insisted.
"I just think Novak played a really good finals. He was super tough and he deserved it at the end."
The Swiss has not lost a set in his march to a seventh US final and his pointedly aggressive approach has served to shorten points and keep the veteran fresh.
Federer has even mixed in a “sneak attack," wherein he occasionally comes up uncomfortably close on a second serve to put his opponent under immediate pressure.
“Now that I have been able to do it also against Stan (Wawrinka), definitely gives me confidence that maybe I can also do it against Novak this way,” Federer said after a semi-finals rout of his compatriot.
Djokovic did not sound like a big fan of the tactic.
“He tried that in Cincinnati. It worked a couple of times. It's exciting shot for him. For the player opposite side of the net, not so much,” he said.
Federer expects a hard-fought match and does not anticipate surprises from Djokovic.
“That's what I like about the rivalry. I don't know how it is for him, but I feel like he doesn't need to adjust his game as much, either,” said Federer.
“I think it's just a straight shootout, and I think that's the cool thing about our rivalry.
“We both can handle each other's (weapons) -- whatever we present to one another, and I think our matches, it's very even.”
Wawrinka becomes fourth player to seal ATP Tour Finals spot
Djokovic, Federer face tough road to US Open final
Wrestler Narsingh wins bronze at Worlds, books Olympic berth
Vinci makes rare list in women's tennis after upset win
US Open women's semis postponed due to rain threat