Andy Murray clinches year-end world No.1 after thrashing Novak Djokovic at ATP World Tour Finals

Andy Murray secured the year-end world number one after overwhelming Novak Djokovic to win the ATP World Tour Finals in London. The 29-year-old cemented his place at the top of the men's standings by thumping the defending champion 6-3 6-4 to take his maiden title at the season-ending tour finals - his ninth of a historic season.

The Wimbledon and Olympic singles champion had won just one of his last six matches with Djokovic, but he started as the chief aggressor and took the opening set following a string of errors from the world number two. An early break at the start of the second eased the British number one into the lead and it was one he would hold to clinch a relatively straightforward victory at The O2 Arena, his fifth title in as many tournaments.

Already the first British player to top the ATP rankings in its 43-year history, Murray ends the season unanimously as the planet's top player with a career-record 24th straight win. The success was delivered as he dismantled the defensive game of the 12-time major winner Djokovic; who looked overawed by the enormity of the occasion for long periods.

"Obviously its a very special day playing against Novak in match like this," said Murray. "We've played grand slam finals, Olympics, it has been a tough rivalry. I have lost many of them. I'm happy to get the win today and to finish the year as number one is very special. This is something I never expected."

The 35th meeting between the world's top two players was fittingly supplemented by the year-end number one being on the line for the first time in the final match of the season. Djokovic had spent 122 weeks at the top of the men's ranking, only to be replaced by Murray at the Paris Masters as he won four tournaments in a row.

Both players had endured vastly different fortunes since their last meeting in the French Open final nearly six months ago, with Djokovic having not won a title since becoming the eighth man to complete the career grand slam. Murray contrastingly had won Wimbledon, Olympic singles gold and 23 straight matches on his way to topping the men's rankings - the first Briton to do so.

But having spent three-and-a-half hours longer on court on his way to his maiden final at the season finale Murray gave away a significant physical advantage to Djokovic, who had dropped just a single set on route to his fifth final in a row. And even in the early stages there were signs Murray was still feeling the affects of his gruelling recent schedule.

Two double-faults in his opening service game contributed to a nervy start for Murray, while Djokovic opened up without dropping a single point on serve in his two games. That run was ended by a fierce flat forehand winner from Murray, which led to the first break points of the contest.

Djokovic's defence was breached as he netted a rising forehand, but Murray repeated the trick as the chance came and went. Then as Djokovic again produced a lacklustre groundstroke, Murray's backhand slice caught the tape. An overshot overhead volley from the Serbian threatened to allow his opponent another opportunity, but the players could not be separated during the first six games.

Clearly heeding the physical chasm between the two players, Murray was the clear aggressor and that approach helped him set up a third break point. This time Djokovic had no reply to Murray stepping in and unloading on his forehand, netting a backhand on the slide to send the assembled crowd into raptures.

Having lost all 19 of the matches in which Djokovic had won the opening set Murray knew he could ill-afford to scupper his opportunity - and he kept his nerve to take the lead. The 2015 Davis Cup winner then cemented that position of authority by breaking at the fourth time of asking in the first game of the second set.

Victory was seemingly all-but assured when after Murray produced a stunning backhand cross-court winner, Djokovic sent a forehand beyond the baseline to drop serve for a second time, as his game began to disintegrate. Typically, the five-time champion had other ideas and cancelled out one of the breaks with some belated deep hitting.

But Murray's lead proved unassailable as he served out the match - with Djokovic saving two match points with an overhead smash and a passing forehand - but the Scot took the third to give his campaign the fairytale finale.