KEY BISCAYNE, Fla. -- In the middle of an intense second-set tiebreaker, David Ferrer held up his finger and stopped playing.
Trailing 3-1, he had been in position to hit Novak Djokovic's forehand, but was convinced that it had drifted long. The replay showed otherwise. Djokovic's shot had clipped the line and Ferrer had committed a fatal unforced error.
Or was it forced?
This is the kind of pressure the world's No. 1 player exerts on opponents. After failing to serve the match out at 5-4, Djokovic seemed a bit irked. And so, he ratcheted up his game -- from merely terrific to sublime -- and won seven of eight points for a 6-2, 7-6 (1) victory in the quarterfinals of the Sony Ericsson Open.
"I am very happy," said the man who has won the past three major titles. "The score line doesn't say much because you have to earn your points against him.
"I couldn't have asked for a better start in Australia. Coming into Miami, I was confident. This is the best match I've played the last couple of weeks in the States."
Men's tennis, in terms of the top seeds, has been running like Swiss clockwork lately.
So, it was a bit surprising when No. 3 Roger Federer, the pride of Basel, went missing in the final four. He was dispatched, oddly enough, by Andy Roddick in the third round. Argentina's fiery Juan Monaco, the No. 21 seed, emerged from the draw's second quarter when he beat Mardy Fish in straight sets earlier in the day.
On paper, anyway, it would appear the world's two best players are destined to meet for the eighth time in 15 months. Spoiler alert: Djokovic is working on a 7-0 streak against Rafa.
Djokovic has won all four career matches against Monaco and 10 of 11 sets. And, considering that Monaco has reached only two ATP World Tour Masters semifinals in 42 tries, it would be an upset of enormous proportions.
The other semifinal, however, has possibilities.
Under ordinary circumstances, Nadal would be a prohibitive favorite. He's won 13 of his 18 matches against Murray. But these aren't ordinary times for the 25-year-old Spaniard.
After scraping past Jo-Wilfried Tsonga 6-2, 5-7, 6-4 in the quarterfinals, Rafa pulled no punches.
"My level?" he asked. "It wasn't one of my best matches. That's the real thing. I really served bad tonight. Much worse than the previous days."
And don't get him started on the nagging knee injury that brought out the ATP trainer in his last two matches.
"I have problems on my left knee," Rafa said. "That's the thing. I'm not feeling great. I don't arrive in my perfect conditions to that match. Always playing Andy is a pleasure for me, and exciting playing against a player like him that push you at the limit."
One day after Nadal confirmed he was stepping down as the ATP player council vice president, the Tsonga match reinforced the necessity of his decision.
For the past year, he's had this one, small problem: Djokovic. Rafa was the No. 1 player in the world until Djokovic stole his crown, beating him six times in 2011 -- all in finals, including the past two majors. The beat went on this year, too, when Nadal fought for 5 hours, 53 minutes in the Australian Open -- and lost again.
Now, it appears Djokovic is the least of his issues.
Outside of that epic match at the Australian Open, here is what has happened in Rafa's three other tournaments:
• He lost to Gael Monfils 6-3, 6-4 in the semifinals at Doha.
• Despite owning an 18-9 career edge over Federer, Rafa fell to him in the final at Indian Wells a few weeks ago by the same score as Doha.
• After a routine opening set against Tsonga, Rafa loosened his grip and almost lost the match.
"I have to recover well," Rafa said. "I have to improve my knee if I really want to have any chance to win."