Rafael Nadal's win over David Ferrer to claim the Mexican Open was astonishing, even by the Spanish player's celebrated standards.
Ferrer perhaps had a bad day at the office, as Rafa himself conceded, but for Rafa to win 6-0 6-2 in just over an hour suggests it must have been a really bad day for Ferrer. Otherwise, we must assume that Nadal is back in the old routine. Maybe Ferrer was struggling, but it is a pretty impressive win for Nadal, whichever way you look at it.
Winning back-to-back in Brazil and Mexico suggests he has returned to some sort of level of his old form. But then he achieved it on clay. Hard courts are a different matter.
The scoreline in beating Ferrer was a shock, but his decision to play at Indian Wells on a hard court is perhaps of greater surprise. He knows what condition he is in, or his people know, but perhaps it is his competitive instinct in wanting to push himself that has governed his decision to commit to the US tournament.
From all that we have heard from him over the past few years, it is hard courts that have been to blame for his plight. And there is no doubt the knees - the left one gives him most stress - suffer the heaviest punishment on such surfaces.
That obviously causes him the greatest damage. Everybody thought he would miss Indian Wells and Miami as he prepares for the French Open and Wimbledon before seeing where he went for the rest of the year.
But suddenly he is doing this. He has not played in a hard court event for 11 months.
I think it is dangerous, but his people know best. Or we have to hope so. He was saying that his knee wasn't too great in Brazil. Maybe they are confident. Maybe they feel they have conquered the problem.
But I would guess there would be an element of risk. We are far away from Rafa and his camp, but as a Rafa fan I was alarmed when I heard he would be playing this week.
Maybe he feels he has to keep playing matches, to keep being competitive and test himself against the top guys. The challenge against Djokovic, Murray or Federer will see how far he has to travel against the very best.
The only top guy he has played competitively in his recovery is Ferrer. It is great that Rafa has come back because four years ago, he looked like he was finished. He came back then and now it looks like there may be a prospect of a return as strong as he ever was.
But this week may tell us truly what condition he is in. It will certainly be much more demanding than his favoured encounters with clay.
We talk about the big four. And the big four are suddenly together again for the first time in nine months when they compete at Indian Wells.
The quartet are ahead of the rest, but then there is Novak Djokovic, who I feel is clear of the other three. I think Djokovic will be concerned that Rafa is back because he is targeting the French Open this year, and must have an outstanding chance of success.
If Novak manages to win Roland Garros, the road will be clear for him to do the Grand Slam this season. I don't know what the stats are, but Djokovic continues to have this extraordinary gift to play well on the big points.
He doesn't seem to get tight. I would love to see him and Murray meet at Indian Wells. That would be the match of the tournament. It was interesting that Murray gave Dubai the miss so you have to imagine he will be in supreme physical condition when he comes back.
But rather than talk about the big four, the nature of Djokovic's Dubai performance in winning a fifth title out of six tournaments since last year's US Open, suggests men's tennis looks like it is more about the big one and the rest.