This one should be fun, particularly after the way last year's match unfolded. At one point in the fourth set, after getting passed by a sizzling forehand, the guy who wins all the sportsmanship awards fired an F-bomb at Murray. There were no hard feelings, but the two do create a certain tension on the court. In a nice way.
There's more pressure on Federer here, because his window is narrowing. He's trying to become the first 32-year-old to win this tournament since Andre Agassi in 2003. Certainly, Federer's serve is as solid as ever; through eight matches this year, he has been broken only five times.
"I don't have doubts anymore," Federer said. "I know I'm going definitely in the right direction. I've had a great offseason. I had a strong end to the year. I couldn't have worked harder in the offseason."
They first met five years ago in Rotterdam -- and the 17-year-old from Bulgaria ranked No. 478 took a set off the four-time French Open champion.
"I remember playing Roger Federer in Miami in 2004, and I was only enjoying the moments," Rafa said afterward. "I felt no pressure. He will certainly be a great player and for sure reach the top 10."
Today, Dimitrov looks to be on the verge of backing up that prediction. After defeating another surprise fourth-rounder, the much-improved Roberto Bautista Agut of Spain, the 22-year-old Dimitrov is already two rounds further in a Grand Slam than ever before. He'll have a tough time with Nadal, who escaped in three sets versus Kei Nishikori in a match that ran 3 hours, 17 minutes.
"I'm really happy to be out there in the quarterfinal," Dimitrov said. "I'm not even close to satisfaction. I've been working really hard in the past year, especially in the offseason.
"We all know that he has won tons of Slams. He's Rafa. But I just want to put myself in position to play those guys. I had tough battles with him in the past.
"I'm quite happy with the way I'm performing so far. So I like my chances."