( CNN ) -- Defending champion Rafael Nadal struggled with a misfiring service and an awkward opponent in veteran Czech Radek Stepanek before battling into the third round of the Masters 1000 event at Indian Wells . Nadal was in deep trouble in the third and deciding set before pulling out a 2-6 6-3 7-5 victory . The world number one admitted that the back problem which affected him during his Australian Open final defeat to Stanislas Wawrinka was still leaving him with doubts . `` I was a little bit scared for the back . I am not yet 100 per cent confident with my service , '' he told gathered reporters after serving eight double faults in the two hour 40 minute encounter . Stepanek , 35 , also posed an unusual challenge as Nadal acknowledged : `` He is not the right player to play against in the first match because what you want to find is rhythm and against him every point is different . '' Stepanek swept through the first set before Nadal hit back to level and take a break lead in the third set . Stepanek broke back then forced three break points on the Spaniard 's service in the sixth game . `` It 's true that with love-40 , I was very close to losing , to being out , but I think I did two good serves and then I played a great point , '' said Nadal . `` Tough one . Anything can happen , but in the end I played well . After that , I think I played better . '' The victory extended Nadal 's record to 41-6 at the Californian event , which he has won in 2007 , 2009 and 2013 . Earlier , third seed Wawrinka came through his first match on the ATP Tour since his triumph in Melbourne , dispatching giant Croatian Ivo Karlovic , 6-3 7-5 without any major drama . `` I was a little bit scared about the way I was going to play , '' said the Swiss , who took time off after his grand slam success . Roger Federer , who is playing in the doubles with Wawrinka , continued his winning run with a 6-2 7-5 victory over France 's Paul-Henri Mathieu . The 17-time grand slam winner is fresh off his success in Dubai , where he beat world number two Novak Djokovic on the way to the title . Britain 's Andy Murray joined the other big guns in the third round with a three set victory , 4-6 6-3 6-2 over Lukas Rosol , but Australia 's Lleyton Hewitt is out , beaten 7-6 7-5 by in-form 17th seed Kevin Anderson of South Africa . In the WTA tournament at the same venue , top seed Li Na beat Chinese compatriot Zheng Jie 6-1 7-5 , while Maria Sharapova returned to tour after her Olympic duties in Sochi with a 6-1 6-4 dismissal of Germany 's Julia Goerges .
Rafael Nadal taken to three sets in Indian Wells opener . Beats Radek Stepanek 2-6 6-3 7-3 in second round match . Roger Federer , Stanislas Wawrinka and Andy Murray also go through . Wins for Li Na and Maria Sharapova in WTA event .