Can Djokovic keep hot streak going?

So now it’s serious.

A little rest, a retention of his own Belgrade title (always a bit of pressure there but he can handle it now) and then back to the big time for Novak Djokovic – two consecutive ATP Masters Series 1000 tournaments in Madrid and Rome for the man who has survived until May without losing a match all year.

That is some achievement. Djokovic’s tally reached 27-0 when he beat Feliciano Lopez in the final of the Serbia Open. And, of course, that run includes the Australian Open as well as Masters Series titles at Indian Wells and Miami. That the Serb has taken a step up this year, physically and mentally, is obvious.

On the evidence he has presented so far, Djokovic is a player without weakness. Just ask Rafael Nadal, Roger Federer, Andy Murray and the supporting cast who are waiting for him at the futuristic Caja Majica in Madrid this week. None of that top trio have been able to puncture the Serbian’s defense.

The setting may resemble Terminal Five at the London airport more than a traditional tennis venue but its three arenas, all with sliding roofs, inside one vast metallic “magic box” is certainly modern and Djokovic, nothing if not a modern player, should feel right at home.

The Serb’s achievements this year are extraordinary. He began the campaign by winning the Australian title, taking out Federer in the semifinal and Murray in the final with the air of a man who had found himself.

That look of authority only grew as Djokovic beat Federer again, 6-3, 6-3, to take Dubai and then Nadal in two consecutive finals to win the Masters Series titles at Indian Wells and Miami. But, and here is the caveat, those triumphs were all on hard courts, Djokovic’s favorite surface.

Can he do it on clay? Winning Belgrade was good preparation but Lopez is not Nadal, nor Federer for that matter, when it comes to the red stuff and Djokovic has no illusions about how difficult it will be to defend that unbeaten record. However, Djokovic is no dunce on clay as he proved in 2008 when he won the Italian title in Rome. And he is a much better player now.

Providing he survives the opening rounds, Djokovic can expect to find himself facing the indefatigable David Ferrer in the round of sixteen and, possibly, Murray in the quarters. Nadal and Federer lie on the other side of the draw.

Nadal, of course, has been looking invincible again on clay, winning Monte Carlo for the seventh time in succession – a record that is likely to stand for a long time – and followed up by winning again in Barcelona. But, if Djokovic wants some encouragement, he can point to the fact that Nadal is not invincible in his country’s capital city. Before the tournament moved to the Caja Majica two years ago, he was beaten by Gilles Simon indoors at the old venue and then by Federer in the first clay court final.

Altitude plays a part here and it is that which Djokovic will hope to exploit against Rafa if he gets the chance.

But there are other people to worry about for the top echelon in Madrid. Juan Martin del Potro won the ninth ATP title of his career in Estoril by outplaying Fernando Verdasco in straight sets and the tall Argentine appears to be returning to his best form after all those months out of the game with a wrist injury.

And, in Munich, there was a 21st career title for Nikolay Davydenko, another player who has been suffering injury problems. But if the Russian can return to the sort of form that saw him win the ATP World Tour Finals in London in 2009, then he, too, will be a threat.

The American contingent was already reduced in numbers by Monday night. Sam Querrey, whose career seems stalled at the moment, lost in a heap 6-2, 6-3 to experienced Frenchman Michael Llodra. And someone had to lose when Mardy Fish met John Isner in the first round. It was Fish who lost out – the 11th seed going down 7-6, 4-6, 7-6. That’s a good win for Isner, who needs a confidence boost after an uneven start to the year.

But the shock came late in the evening when Andy Roddick suffered a shocking loss in first match of the year in Europe when he went down 6-4, 6-7, 6-3 to a 27-yearold Italian called Flavio Cipolla who is currently ranked 160 on thre ATP ranking and has never been higher than 99. Cipolla had worked his way through the qualifying at both Estoril and Barcelona in previous weeks but had lost in the first round of both tournaments in straight sets — first to Frederico Gil and then to Robin Haase.

But Cipolla evidently found it easier against Roddick who is not the first American to fall to the wiles of a European clay court expert and he won’t be the last.