* Djokovic wins 6-3 6-4 to improve Beijing record to 19-0
* First hard-court-loss of 2013 for number one-elect Nadal (Adds quotes, details)
Oct 6 (Reuters) - Novak Djokovic won his fourth China Open title in five years on Sunday, prevailing 6-3 6-4 in the final against Rafael Nadal who will replace him as the men's world number one on Monday.
The Serb continued his love affair in Beijing, improving his tournament record to 19-0 after brushing aside Nadal to halt his run of three defeats against the Spaniard.
Nadal had to reach the final in the tournament to displace Djokovic from the top ranking and the issue was put to rest on Saturday when Tomas Berdych retired with a back injury in his semi-final against the Spaniard.
"I needed this win today," Djokovic told reporters. "I really wanted to get my hands on the trophy and win against Nadal, who has been the best player so far in 2013.
"It's very important for my confidence. It's very important mentally and emotionally for me."
The 26-year-old Djokovic stamped his authority on the title match early, racing to a 3-0 lead and never allowing the Spaniard, who went into the match unbeaten on hard courts this year, to stage a comeback.
The Serb broke Nadal, who has won 10 tournaments and added over $10 million in prize money in 2013, in the first game of the second set - hitting winners almost at will.
Since winning the Monte-Carlo Masters in April against Nadal, Djokovic had lost to the left-handed Spaniard in the French Open semi-finals, the Rogers Cup semi-finals and the final of the U.S. Open.
"I managed to stay tough and not drop my concentration, which I think (happened) in both Montreal and at the U.S. Open in the important moments," Djokovic said.
"I learned my lesson. It was a few very tough and close matches that I lost against Rafa on hard courts, especially the last one in the U.S. Open final."
Such was Djokovic's domination that the 27-year-old Nadal, who boosted his grand slam singles tally to 13 this year by winning the French and U.S. Opens, failed to create a single break point opportunity in the whole match.
"I didn't see the way to stop him this afternoon," Nadal said. "This afternoon he was too strong for me. I didn't play my best match, but he played at a very high level with his serve.
"I was not able to have any chance when I was returning during the whole match. He had the ball staying very low. It was very difficult to create spin on this ball.
"He was able to hit all the balls where he wanted. When that's happening against a player like Novak, you are dead. You don't have not one chance."