We have been here before, but this time there is a subtle difference.
When Rafael Nadal and Roger Federer square up in the semi-finals of the Australian Open tomorrow, it will be the 10th time they have faced each other in a grand slam event, equalling the record set by Ivan Lendl and John McEnroe in the 1980s.
However, it will be the first time since the 2005 French Open that the two most successful players of their generation have met in a grand slam event before the final.
"We have been on opposite sides of the draw many times," Federer admitted. "I didn't even play [Andy] Murray last year because we were ranked No.3 and No.4 so I basically always ran into Novak [Djokovic].
"It's a nice change. Okay, it doesn't allow for a rematch of the Australian Open final if Murray were to play Novak. But I think it's good for tennis that it changes up a bit."
Murray and Djokovic were due to play their respective quarter-finals last night, with Murray taking on Japan's Kei Nishikori and defending champion Djokovic playing world No.5 David Ferrer, of Spain.
Federer's 6-4, 6-3, 6-2 victory over Juan Martin Del Potro in the quarter-finals yesterday took him into the last four without dropping a set and extended his winning streak to 24 matches.
In what was his 1000th career match – "I wish it was 1000 wins but I'm happy with 1000 matches in total, too," he said – Federer looked close to his very best, never allowing Del Potro the chance to get a foothold in the match.
While Federer breezed through in less than two hours, Nadal took more than four hours to shake off Tomas Berdych, finally winning 6-7, 7-6, 6-4, 6-3 to book his place in the semi-finals for the first time since he won the title three years ago.
Nadal spent most of the first two sets against Berdych pinned behind the baseline. The Czech snatched the first set and had a chance to win a second tie-break, only to miss a very makeable backhand volley on set point.
That gave Nadal his chance and he took it. After that it was largely one-way traffic and, by the end of the match, the Spaniard was playing the kind of strong, aggressive tennis he will need when he comes up against Federer.
"I think the level of the third and fourth sets for me was very, very high, at the top level for myself playing on these courts," Nadal said.
"The level is very positive, much, much better thanit was at the end of last season. The character on court, the way to win the points, everything was much more positive, so I'm very happy."
Whoever is considered the favourite on paper when these two take to the court, nothing can be taken for granted. The two men have won 26 grand slam titles between them and there can be little either does not know about the other's game.
What is certain is that the game will be intense from the outset. Federer leads their hard-court meetings 9-4 but Nadal leads 17-9 overall. The important thing, however, is that both players seem fully fit and are playing well.
"I'm really happy with my game," Federer said. "I'm moving well. I'm serving well. I'm hitting the ball well."
And a final word from Federer on joining an elite group of players to have competed in 1000 matches?
"It's a big milestone, I agree," he said. "It's a lot of matches and certainly a lot of tennis.
"Either I have been around for a long time or I'm extremely fit. You decide which way you want to describe it. I don't know, but I'm very happy."