Rafa was cruising until the beginning of the second set, when the wind kicked up.
Considering the unbelievably violent way he strikes the ball on the forehand (and part of the time on the backhand as well) and the exquisite timing it takes to do that, it's a testimony to Rafa's unparalleled athleticism that he hits the ball cleanly on a consistent basis. Other people simply can't do that with the sort of swings Rafa routinely delivers.
So, in a "normal" (for him) performance, Rafa had the whopping total of 3 unforced errors in the entire first set! But then the wind kicked up and caused both players problems. Clearly it was a gusting, inconsistent wind that made it hard to know where the ball would be and when. The spectacularly high quality of play in the first set gave way to errors, and then to both players trying to find ways to avoid those errors while continuing to play aggressively.
When you're playing Rafa, you know he's going to run down and return balls nobody else can get to, and that he is not going to give you anything (because of his determination and consistency). You know he's going to raise the level of his play considerably on the big points. Everybody knows all of this: players and fans alike.
What is not so obvious is that, no matter who you are, Rafa is going to out-think you as well. You saw that today, as he did a better job than Tomas of solving the puzzle created by the wind. He dialed it down a notch, increased his variety and gave himself more margin of error than usual -- and he always has a higher margin of error than anyone else. Once he got a feel for where the ball would be, he upped the aggression level. Brilliant stuff.
And his knees held up sufficiently to get him through the tournament. So the good news for the Nadal camp just keep getting better, but the knee issue continues. I was distressed to hear Rafa say that he's only going to take two or three weeks off, and to speak as though he intends to play Canada and Cincinnati. That is an absolutely horrible idea. McEnroe had earlier said that Rafa was going to take 5 or 6 weeks off, which would be perfect: get some treatment, let the knees heal, minimize time on hard courts. I sincerely hope that Rafa does what McEnroe said he would do rather than what Rafa said he intends to do.
It would be a shame if such a great player had his career cut short because he failed to take proper precautions to safeguard his health.