If Andy Murray was nervous ahead of his first match as World No.1, he didn’t show it. He was up against a dangerous opponent in Marin Cilic who had come out on top in their previous encounter in Cincinnati, and he was playing Tennis on a stage which hasn’t always felt like home.

World number one

Murray’s record in London’s O2 Arena, host of the ATP World Tour Finals since 2009, reads eight wins versus ten losses. His best result is the semi-final. Last night’s performance suggests he is more than capable of rewriting history this week.

He dismissed the big-hitting Croat Cilic 6-3 6-2.

It was a wonderfully controlled performance befitting of the world No.1. Murray was ruthless. Speaking to Sky Sports after the match, Cilic said he thought he’d “played quite well” despite only taking five games from the Scot.

The scoreline shouldn’t disguise the fact that it was a competitive match with plenty of tight moments – Murray simply prevailed in the key points as the best players tend to do. Kei Nishikori had beaten Stan Wawrinka earlier in the day by the same score, but Wawrinka’s inconsistency meant that match was far less of a spectacle.

The manner of Murray’s victory was reminiscent of his key rival and previous No.1 Novak Djokovic, who has won the last four titles in London.

Murray's meteoric rise

Murray has produced the best six months of his career to claim the No.1 ranking from Djokovic. After beating Murray in the French Open final in June, the Serb became the first man in nearly half a century to hold all four major titles at the same time. He had a seemingly insurmountable lead in the rankings.

But since rekindling his partnership with former coach and world No.1 Ivan Lendl in the summer, Murray’s results have been outstanding. He won his second Wimbledon title in July, followed by an Olympic Gold Medal in Rio.

He has maintained his red-hot form through the latter part of the season, winning his past four tournaments across Asia and Europe.

Djokovic’s form has dipped in the meantime, perhaps inevitably following his career-defining title at Roland Garros.

Murray’s rise has not just happened over the past six months, however. It is the result of years of competing at the very top of men’s tennis.

He has been unfortunate enough, or fortunate depending on your view, to be born in an era which contains three of the all-time greats. Since Roger Federer rose to No.1 in 2004, only he, Rafael Nadal and Djokovic have been ranked at the top. Between them, they have won an eye-watering 43 Grand Slam titles. The fact Murray can call himself the best while they’re all around is thanks to a career of hard work and sacrifice.

Still work to do

To hold onto the top ranking, Murray is likely to have to win this week’s season-ending showpiece.

His Serbian rival Djokovic is looking to equal Federer’s record six year-end titles. He has won the past four and is firm favourite to be staring over the net should Murray make the final.

That is far from a certainty. Murray has undoubtedly been given a tougher draw than Djokovic. Whereas the Serb is grouped with three opponents who he has never lost to in a combined 23 meetings, Murray faces in-form Japanese Nishikori and US Open champion Wawrinka after overcoming Cilic.

But judging by last night, Murray has no intention of relinquishing the No.1 ranking. He has well and truly earned it.