Rafael Nadal overcame a shaky start to beat Czech Tomas Berdych 2-6, 6-2, 6-4 in the Swedish Open final on Sunday and win his seventh title of the year.

The 19-year-old took his remarkable claycourt winning streak to 29 and became the first man to win seven titles on clay in one season since Thomas Muster in 1996.

He has not lost on the surface since Valencia in April when eventual champion Igor Andreev beat him in the quarter-finals.

Nadal looked nothing like the French Open champion in the first set with Berdych breaking his serve three times.

Using his 1.93 metre height to cope with Nadal's heavy topspin shots, the Czech fired winners past the Spaniard on both sides and kept many rallies short with his booming serve.

Nadal found his groove and overran the Czech in the second set to take the match into a thrilling decider where he proved stronger than Bercych, breaking him to 3-2 and serving out to love for 4-2.

Berdych fought back bravely but failed to convert a break point when Nadal served for the match at 5-4 and the Spaniard sealed victory on his first match point.

"I didn't play too well today, but Berdych was tough and aggressive," said Nadal. "In the first set he played so good I couldn't do much."

"I played a little bit more aggressively in the second set and I played with deeper shots. I got 4-0 very fast and that was important for the confidence."

Nadal's claycourt tally this year is 43-2 but he will remain third in the rankings behind Roger Federer and Lleyton Hewitt.

Asked about whether the number one spot was a goal of his, the Spaniard said: "I'm not ready for it. I need to improve in my game. I will need to improve my serve and find regularity in it and I have to become more aggressive on my forehand."