SEPANG, Malaysia - Kimi Raikkonen returns to the scene of his first Formula 1 victory fresh from a season-opening triumph in Australia. While he mastered Melbourne he expects a completely different challenge in Malaysia.The Lotus driver claimed the first of two wins at Sepang with his maiden victory in 2003 and after enjoying a routine race at Albert Park on March 24, the taciturn 33-year-old expects heat and rain to play major roles in the second round.'IT'S PROBABLY GONNA RAIN'Raikkonen said: "It's a difference place, it's going to be much hotter, so it's very difficult to say how the cars will feel and who will be fastest after having done just one race. "It's probably going to rain again in Malaysia at some point but it will be a different circuit, different conditions."He managed the rapidly-degrading Pirelli tyres to perfection as his rivals toiled in Melbourne. Raikkonen, the 2007 world champion, has now scored points in the last 18 grands prix.He said: "Our car worked well in Australia and usually, at least in 2012, in hot conditions it's been good for us, so hopefully it will turn out to be a good weekend."Raikkonen was installed as a world title contender after cruising through the field from seventh on the grid before seeing off the challenges of Fernando Alonso and Sebastian Vettel, a judgment the Finn believes was far too early to call.He said: "I think we have to do two or three races before we really know who is where and what's going to happen.""Of course, I'm happy that we didn't really have to go full speed all the time so it's kind of a good sign, a good race for us, but as I said, it might be a completely different story in Malaysia."Ferrari appear far better prepared for the campaign after a smoother pre-season than its campaign in 2012 and enjoyed a solid opening race with Spaniard Alonso finishing second and Brazil's Felipe Massa fourth.STRANGE CONDITIONSHowever, double world champion Alonso remains cautious of his chances of grabbing a victory in the opening four races before the 19-round series heads to Europe for the Spanish Grand Prix in May.Alonso, who won the 2012 race in Sepang, said: "It will be a surprise to be honest if we win one of the first races."It will be welcome for sure, but we need some strange conditions - maybe like last year in Malaysia, rain or something. But in normal conditions, I think the podium is more or less the maximum target we have to ask."For Vettel, Melbourne was a disappointment after the defending world champion dominated practice and qualifying only to see his Red Bull struggle with tyre wear over the long runs during the race.Red Bull team principal Christian Horner is refusing to panic despite the car's underwhelming performance in Australia and believes it will take four or five races to get an accurate picture of form.Horner said: "I think we learnt an awful lot and hopefully it won't be quite as chilly next weekend. The really positive things are that we've got a quick car and we've qualified on pole."I think we're only going to get a true picture of form after about four or five races when we've been to different venues, different tracks, different asphalt surfaces."