LONDON — As usual this season, Novak Djokovic was the best player on the court.
The top-ranked Serb won his fourth straight title at the season-ending ATP finals on Sunday by beating six-time champion Roger Federer 6-3, 6-4.
Djokovic, who won three Grand Slam titles this year and reached the final in the other, capped the best season of his career with another superb display, including winning 16 of the 19 points on his second serve and saving both break points he faced.
"This could not have been a better finish," Djokovic said on court after the match. "Obviously it's been a very long season but the best of my life."
Federer beat Djokovic on Tuesday in the group stage, but the 17-time Grand Slam champion made too many mistakes in the final on Sunday. Federer ended up with 31 unforced errors, including 15 from his usually reliable forehand.
He even gave away the final point with his second double-fault of the match.
"Tried my best this week. I thought I played some great tennis even in the final," Federer said on court. "Some points were crazy, but Novak deserved the win today like he has so many times this year.
"Congratulations on a ridiculously good year."
Federer finishes his season with a 6-5 record in finals, with all five losses to Djokovic. Two of those of those came at Wimbledon and the U.S. Open, giving Djokovic his ninth and 10th major titles.
For Djokovic, it was a season to remember.
Besides becoming the first man to win four straight titles at the tournament for the top eight players in the world, Djokovic also will finish the season at the No. 1 player for the fourth time in five years. He won the Australian Open, Wimbledon and the U.S. Open, and reached the final at the French Open.
The latest victory, his 82nd of the year, evens the head-to-head record against Federer at 22-22. On Saturday in the semifinals, he evened his head-to-head record against Rafael Nadal at 23-23.
On the court, both Djokovic and Federer had break chances in the opening two games, but both managed to save them.
The first breakthrough for Djokovic came in the third game. With Federer serving at 30-30, the Swiss player thought he had his first ace of the match. But Djokovic challenged the call, and won.
After a long rally from the second serve, Djokovic hit a backhand winner to get to break point, and then Federer put a forehand into the net.
Djokovic broke Federer's serve two more times, first to win the first set and then to win the second when Federer double-faulted.
Chris Lehourites, The Associated Press