Impressive Nadal beats Berdych in semi-final INDIAN WELLS, California (Reuters) - Looking as though he had never been away, Rafa Nadal continued his impressive comeback with a high-quality 6-4 7-5 victory over Tomas Berdych in the semi-finals of the BNP Paribas Open on Saturday. The Spaniard, who returned to the ATP circuit only last month after seven months out with a left knee injury, broke the Czech once to take the opening set, then won a tense second set to improve his record this year to a career-best 16-1. Nadal, who won the last four games to come from 3-5 down in that second set, will next meet either top-seeded Serb Novak Djokovic or Argentina's Juan Martin Del Potro who were playing their semi-final later on Saturday. "For me this is totally unexpected to be in the final," a beaming Nadal said courtside after beating the sixth-seeded Czech for a 13th time in 16 meetings. It is a big surprise, but I am here. I had to play aggressive today. Twice a champion at Indian Wells, Nadal looked every inch like his former self, hitting crisp and deep ground strokes to keep Berdych under continual pressure and occasionally unleashing his trademark inside-out forehand crosscourt winner. On a sizzling hot afternoon at the Indian Wells Tennis Garden, the opening set went with serve until the seventh game when Berdych double faulted, hit a forehand long and dumped a forehand into the net to trail 0-40. Though the Czech saved the first two break points on forehand errors by Nadal, he lost the game on the third when he blasted a forehand wide as he hungrily eyed a winner down the line. The Spaniard served out to take the set in 42 minutes, applying the finishing touch with a well-placed 119 mph service winner that Berdych was unable to return. It was the first set the Czech had lost during the tournament. Both players held serve until the eighth game of the second set when Nadal, despite getting a favorable net cord bounce as he tried to save his first break point of the match, double-faulted to trail 3-5. However, the Spanish left-hander immediately broke back, after Berdych hit a forehand long, before holding to level the score at 5-5. Nadal then broke the Czech for a third time in the 11th, squandering his first break point at 30-40 but taking advantage of the second when Berdych mistimed an overhead as he gazed up into the sun, the ball careening off his racket and bouncing well beyond the baseline. The tension mounted as Nadal served for the match in the 12th game, the Spaniard coming back from 0-30 down and saving three break points before he sealed victory on his second match point when Berdych pushed a backhand wide. Nadal leaped in delight with both arms raised in celebration as he advanced to the final at Indian Wells for a fourth time. "The biggest difference was in the second set when it was 5-3, and since that time I serve only one first serve and he serve only one second serve," a dejected Berdych told reporters. Actually, that was the difference today. Asked if Nadal had looked like the Rafa of old with his movement about the court, Berdych replied: "I think so. He was moving quite well. Maybe he will say something different because it's him, his body, and he has a feeling for that, but I think he looks strong again.