Andy Murray became the first British player to top the rankings since the system was introduced in 1973. (Photo: AP)

Andy Murray insisted he was taking nothing for granted going into the Tour Finals in London next week after overtaking Novak Djokovic as the new world number one.

The 29-year-old celebrated his coronation by claiming a 14th Masters 1000 title on Sunday with a 6-3, 6-7 (4/7), 6-4 victory over American John Isner in Paris.

His career-best eighth tournament win of the season came just a day after Murray became the first British player to top the rankings since the system was introduced in 1973.

“It might only be for one week. So I might as well try and enjoy it because I could lose it at the Tour Finals and never be there again,” said Murray.

He moves 405 points above Djokovic in the latest rankings, but the Serb could regain his place at the top if he goes undefeated to land a fifth straight Tour Finals crown.

“I wasn’t thinking so much about the cushion or anything like that at the top. I’m obviously happy I got there. It would be nice to finish the year no. 1, but I’m happy that I managed to get there,” added Murray.

The Scot has struggled in London of late, exiting at the round robin group stage twice after missing the 2013 event through injury.

“The last couple of years have been tough there for me. So, yeah, obviously I want to try and play my best tennis there.

“It’s not necessarily about winning. I just want to play my best and finish the year on a good note in that respect, because some of the years it has been tough for me there.

“So hopefully I can play some good tennis there. I will take a few days’ break now, and rest up a little bit and get ready for one big push out of the next 10 days.”

With Roger Federer and Rafael Nadal both sidelined, and Djokovic considerably short of his best, Murray will head into next season with lofty expectations.