There's still plenty to improve on grass for the king of clay, says Brian Dick...
Rafael Nadal is the only tennis player on the planet between Roger Federer and invincibility. He is just the second man in the professional era to win a Grand Slam in both of his first two appearances and at the age of 20 he has already claimed 17 singles titles. He is a phenomenon.
But he is one whose feats are made on clay. At no stage yesterday in his enthralling five-set victory over American Robert Kendrick did the double French Open champion look like someone who would keep Federer awake at night.
Nadal has much to learn about playing on grass both technically and mentally.
On the red stuff that predominates in Rome, Monte Carlo, Barcelona and Paris - where he has won in 2006 - not even the Swiss legend can live with him. But on grass Kendrick showed that no one need fear the Spaniard.
Ranked 237 in the world the American No 26, was a dog having his day yet with his pedigree - his first round victory over Yen-Hsun Lu was the first Grand Slam win of his career - and at 26-years-old he is a tennis mongrel who Nadal should have put down.
That he failed to do so convincingly, eventually prevailing 6-7, 3-6, 7-6, 7-5, 6-4, said a lot about the Majorcan's deficiencies on this surface and must be compared to the way Federer swatted aside Tim Henman's challenge on Wednesday.
Henman is a grass court specialist who, with Nadal, is one of the only men on the circuit to enjoy his end of the head-to-head ratio with Federer. He was playing in his home Slam and was backed by a partisan crowd. Yet Federer destroyed him.
Which begs the question what would he do to Nadal? On this form Rafa need not bother turning up. He was as effective as the line judge who fainted 11 minutes into this match.
The fact Nadal recovered from two sets down should be applauded. It is only the second time in his embryonic yet prolific career that he has managed that. In doing so Nadal showed over the course of three-and-three-quarter hours the resolve he brings to every point on clay.
But Federer will be salivating at the prospect of getting to grips with the man who has beaten him on six of the seven occasions they have met, including the last five.
Imagine what the three-time champion will do to one of those heavily top spun forehands of his as it floats across the net. He'd ram it back whence it came, that's what.
Yesterday the Nadal first serve averaged just 114 miles per hour, his second a mere 94. At Roland Garros the service is just a way of getting the ball into play. At Wimbledon it should shape the point.
And so it will when Federer smears it back and takes control of the net the way Nadal allowed Kendrick to do.
Unless Nadal's recent supremacy has left a few psychological scars any encounter between the world's top two players could be messily one sided.
But then it cannot happen until the final and while Federer will be hot favourite to get make his fourth in succession. Even though he is seeded two it would be something of a surprise if Nadal came through a half containing Andre Agassi, Ivan Ljubicic and Lleyton Hewitt.
Early on Kendrick gave him immense trouble as he raced into a two set lead, coming back from 4-1 down in a first set tiebreak to win it with six straight points.
Nadal sacrificed his serve in the second game of the second set, never recovered and lost the stanza 6-3. When he received a time violation at the start of the third he could have crumbled.
But instead he began to exert more pressure on the Kendrick serve and took each of the American's games to 30 or beyond into another breaker. This time he took control, built up a 5-1 lead and closed out at the first opportunity.
The momentum had swung. The fourth set was taken 7-5 and when Kendrick double faulted at love-40 in the fifth game of the decider, the dam had sprung.
Afterwards Nadal was keen to put the match in perspective.
"It is important for me to have a lot of hours on grass," he said.
"I have put a special goal in the next two, three or four years to play a very good tournament here. I don't know if I'll do it this year.
"If I play more matches on this surface against big servers that is important for my improvement."
As would a masterclass from Federer, if he can reach it.