World number one Andy Murray switches focus to adding to Grand Slam collection
Andy Murray set his sights on adding to his three Grand Slam titles after securing the year-end number one ranking with victory at the ATP World Tour Finals.
The Briton, 29, beat Novak Djokovic 6-3 6-4 in London to ensure he will stay ahead of the Serb heading into 2017.
"Now that I've got there, I obviously would be motivated to try and stay in that position," said Murray.
"But the majors get me working hard - they really, really motivate me."
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Murray, 29, won his third major title at Wimbledon in July, and ended the year on a 24-match winning streak that culminated with victory over Djokovic at the O2 Arena.
He will now take a break, including attending his father Willie's stag do, before turning his attention to the new season and the Australian Open.
Djokovic is a six-time champion in Melbourne and has beaten Murray in four of the five finals the Scot has lost there.
"When I go away in December to train, I'm training with the Australian Open in mind," said Murray.
"Because of the best-of-five-set matches, they're the ones you have to really put in the extra work for and the extra training for. That's what motivates me."
With the year-end number one ranking on the line, and having a 24-10 losing record against Djokovic, Sunday's victory at the O2 Arena was especially significant.
"It was obviously a big, big match against someone who I've played so many big matches against in my career, that would be my main rival really throughout my career," said Murray.
"We've played in all of the Slam finals, Olympics, obviously here now, and a match to finish the year number one. It was a very important win for me."
BBC's tennis correspondent Russell Fuller
Murray showed no obvious signs of fatigue in the early stages, and as he started to play with a little more aggression, Djokovic's errors began to mount. Murray controlled this match as he has virtually every one he has played since May.
The win over Djokovic - just his third since Wimbledon 2013 - will allow him to start 2017 on the front foot in their long term rivalry, and as he chases that elusive first Australian Open title.
Murray's lead in the rankings may be small for now, but it could be significantly bigger by the spring as he has relatively few points to defend until then.
'Let Andy enjoy this a little bit'
Djokovic, 29, has suffered a slump in form since completing the career Grand Slam by beating Murray at the French Open in June, and was below his best again on Sunday.
"There was no serious chance for me to win today's match," said the Serb.
"From the very beginning we could see that. He was just a better player all in all. It just wasn't my day.
"On the other hand, credit to Andy for being mentally tough and playing the right shots, making me play extra shots in every rally. He definitely deserved to win."
And Djokovic paid tribute to Murray's wife Kim, who gave birth to their daughter Sophia in February.
"We should all let Andy enjoy this a little bit," he said.
"Don't ask him questions about next season. He deserves to be in the moment and to really take everything in that he achieved.
"His team as well, and his wife. She has to get some credit, guys. She gave birth this year. He has travelled all over the place.
"I know how it is with my wife Jelena, what she had to go through as a mother back home with a little baby.
"So, Kim, well done. She's maybe made even a bigger effort than Andy."