Roger Federer takes on Juan Carlos Ferrero in Friday's Australian Open semi-final knowing victory will make him world number one.
Federer could become number one for the first time on Friday
Andy Roddick's defeat to Marat Safin has left Federer and Ferrero to fight for the top spot.
The Spaniard needs to win the title to reclaim the number one ranking he held for eight weeks last year.
Second seed Federer will take over at the top for the first time if he sees off Ferrero.
"I can't say much," said the Swiss. "I don't want to because I'm focused on winning this tournament, especially now I have made it to the semi-finals.
"The number one is secondary right now."
And Wimbledon champion Federer is confident of getting past Ferrero, despite sharing a 3-3 career record against the Spaniard.
"Ferrero's game is much more simple, it kind of makes the game easier," said Federer.
"I'm confident now. I feel like I've definitely got the game to beat him."
French Open champion Ferrero admits he is desperate to get back to the top of the rankings.
"Of course, of course," he said. "I am very motivated to try and get it again. I am very close to the number one.
"Because Roddick is out of the tournament he loses some points. I am in the semi-finals with the chance to go into the final and get closer to number one again."
And the 23-year-old insists he does not mind the lack of fanfare that surrounds his progress when compared to Federer.
"People don't want to talk about me, I don't know why," he said. "I'm playing very solid, so I think I have a chance to win.
"Roger is a very talented guy - he can play any shot he wants. It's always difficult to return his serves.
"Roger just does amazing shots whenever he wants."