Fourth seed Rafa Nadal survived a few anxious moments before booking his place in the semi-finals of the BNP Paribas Open with a see-sawing 6-4 6-3 victory over Japanese Kei Nishikori in California on Friday. The Spanish left-hander, a three-times champion at Indian Wells, will next meet top-seeded Serb Novak Djokovic, who battled past Frenchman Jo-Wilfried Tsonga 7-6(2) 7-6(2) in the last of the quarter-finals. Djokovic, the world number one and defending champion, improved his stellar record for the year to 20-1 as he seeks a fifth title at Indian Wells. Nadal fought back from 1-3 down and 15-40 on serve in the opening set, then held off a late fightback by Nishikori in the second to prevail after a little more than an hour and a half at the sun-baked Indian Wells Tennis Garden. 'The first set was very important,' 14-times grand slam winner Nadal said in a courtside interview with ESPN. 'At 15-40 for one double break for him, that was the key moment and after that I started to play with higher balls, slower balls. 'I changed a little bit the rhythm of the match and I think I played well.' After levelling at 4-4 in the first set, Nadal won the next five games to take command before his fifth-seeded opponent clawed his way back with a break in the seventh to trail 3-4. Nadal, however, immediately regained his advantage in the eighth game after Nishikori netted a backhand, and the Spaniard served out for the victory, ending the match with a forehand winner down the line. Djokovic delivered his usual blend of brilliant defence and precise shot-making to wear down an error-prone Tsonga in a match that lasted just over two hours. The Serb failed to close out the first set when he served at 5-4, but dominated the tie-break as the Frenchman paid the price for a typically high-risk strategy. Though Tsonga broke Djokovic in the third game of the second set, the Serb immediately levelled at 2-2 before going on to lead 5-4. The Frenchman saved two match points in the 10th game with booming forehands to take the set into another tie-break but again lost momentum with erratic play and the match ended when he blasted a forehand service return wide. 'The experience, the self-belief and knowing that I have done it before ... helps to get the engines going,' said Djokovic, who benefited from Tsonga's 47 unforced errors. 'I really try to do well in the moments when the match is going to be decided.' The second semi-final at Indian Wells on Saturday will be contested by Belgian David Goffin and big-serving Canadian Milos Raonic, who won their matches in the last eight on Thursday to advance.