Jonas Bjorkman: Andy Murray deserved to be No. 1

Thiem won first set on a tie-break but the Serbian star battled back to win 6-7 (10-12) 6-0 6-2.

23-year-old Thiem found it hard to return Djokovic’s serves early on but grew into the game as the first set wore on, hanging onto his own serves to take the match into a tie-breaker.

In the opening match of the traditional season-ending tournament, Djokovic was warned for unsportsmanlike conduct when he smashed the ball in the direction of his box after losing the first set.

Djokovic has lost only one match here in four years, winning the title on each occasion, but he will surely have to improve if he is to maintain that record after an unconvincing 6-7 (10/12) 6-0 6-2 win over the eighth seed. Following a one-hour and nine-minute opener, the second set lasted only 23 minutes.

Djokovic has won only one of his six tournaments since Roland Garros, with lackluster exits from Wimbledon and the Rio Olympics leaving some to whisper about problems in the Serb’s private life and question the influence of “spiritual guru” Pepe Imaz. With a win in London, he could still make it five out of six years.

“But I think that’s a positive thing. I just feel a lot more stable throughout the year”. A forehand error by the No. 2 seed put him in another hole at 10-11 and this time Thiem capitalized on his set-point opportunity it with a big forehand victor. He started making more errors, which I used.

Victory in the capital would ensure the 29-year-old finishes 2016 as year-end number one, but he could face a possible dislodging from the top of the pile by Novak Djokovic, should the Serb go further in the tournament than Murray. Murray appeared to be feeling the effects of his Olympic gold medal won the previous week as he suffered just a third loss in 14 career meetings with the Croatian having beaten him in three sets on the way to the title at Queens in June.

Djokovic said: ‘I definitely didn’t want to let him start off well in the second set. The withdrawals of Roger Federer and Rafael Nadal has opened doors for the likes of Dominic Thiem and Gael Monfils who will be taking part in their maiden World Tour Finals.

“I lost a little bit of energy, not much, but just a little bit (after the first set)”, Thiem said.

“This year is the best I’ve had on court, the last few months have been the best in terms of my consistency”.

Djokovic squared the match without dropping a game in the second and broke Thiem’s resistance again in game three of the decider to put him on course for victory.

Cilic did not have a very good start to 2016 but began to improve during the grass-court season as he reached the semis of the Aegon Championships and his third successive quarter-final at the Wimbledon where he almost defeated seven-time victor Roger Federer.