It's a rivalry that's been so riveting for so long it has a nickname.
Roger Federer vs. Rafael Nadal.
But the fact is this is a rivalry that has swung so heavily to Nadal that it's Rafa most of the time, heck, nearly all of the time now.
And when it matters most.
Nadal beat Federer again today, this time in the semifinals of the 2012 Australian Open in another four-set slugfest that if not an epic - what could ever come close to matching the 2008 Wimbledon final? - was certainly a stirring thriller.
"It was another, I think, fantastic match," said Nadal afterwards.
Except we pretty much know the ending every time now, don't we?
Nadal will get to be the only player in tennis history, it seems likely, who will be able to include in his epitaph the phrase, "I owned Roger Federer."
Today's 6-7 (5), 6-2, 7-6 (5), 6-4 triumph in three hours, 42 minutes was the 27th match all-time between the Swiss and the Spaniard, and Spain's colors have now risen in victory in 18 of those matches.
In Grand Slam events, Nadal's dominance is more pronounced, as he is now 8-2 against Federer. The last time Federer defeated Nadal in a major was way back in 2006 at Wimbledon, nearly six years ago, and Nadal has won nine of their last 12 meetings.
That's owning a guy.
At 30, Federer is still among the top four players in the game along with Nadal, Novak Djokovic and Andy Murray, arguably the most talented foursome in the history of the men's game.
But his age also means Federer has virtually no chance of swinging "Fedal" back in his favour. In fact, his chances of winning another major are dwindling. He's now gone eight Grand Slam events without winning one, and with Nadal dominant in their matchup and Djokovic now the No. 1 player in the world, Federer's odds of winning another big one are getting long indeed.
There were some tactical differences in today's match, with Federer hitting his backhand down the line to Nadal's backhand to change some of the patterns from other matches. But the featured elements were the same; Federer charging ahead but unable to hold leads, and Nadal running off the court and then making unbelievable winning shots from impossible positions.
In this match, Federer was up a set and a break and couldn't hold it. He was up a break again in the third set. But he made a bushel of double faults, self-destructed in the third set tiebreak and couldn't capitalize on a couple of break points in the final game to extend the match.
"He just doesn't believe his best is going to be good enough to beat Nadal," opined tennis commentator Patrick McEnroe.
Federer and Nadal had, in many eyes, openly clashed in the opening days of the tournament in separate press conferences when Nadal appeared to criticize Federer over the handling of some sensitive internal ATP issues. But when this match ended, they shook hands warmly at the net, Nadal applauded along with the crowd when Federer made his exit and then, as he often does, paid homage to the pride of Switzerland as the player who made him better.
"I always saw one player better than me in front of me," said Nadal, who has battled right knee problems throughout the tournament.
Nadal now faces the winner of the semifinal contest between Djokovic and Murray. Asked to discuss the match, he advised Murray to play more aggressively, but then added: "But my advice is not worth much because (Djokovic) has beat me six straight times."
The women's final, meanwhile, is set between Maria Sharapova and Victoria Azarenka, the two loudest "grunters" on the women's tour in what promises to be a tight match and a shriek-fest that could be painful to the ears. Azarenka ousted Kim Clijsters in what most believe was Clijsters' farewell match at the Aussie Open, while Sharapova eliminated 2011 Wimbledon champion Petra Kvitova.