LONDON - Andy Murray fought past a dogged David Ferrer to win his opening match at the ATP World Tour Finals on Monday, showing no sign of being distracted by next week’s Davis Cup final in Belgium.

The Briton needed to be at full tilt to finally subdue his Spanish opponent 6-4 6-4. After Sunday’s two opening singles in the other group saw easy wins for world number one Novak Djokovic and Roger Federer, Murray and Ferrer produced some absorbing rallies in a near-capacity O2 Stadium.

World number two Murray took the first set when Ferrer, trailing 4-5, served a double-fault. But he was broken to love at the start of the second set and 33-year-old terrier Ferrer seemed to have the bit between his teeth before dropping serve in the sixth game. A confident Murray piled on the pressure and Ferrer again buckled at 4-5 with Murray completing victory with a volley into an open court.

Novak Djokovic made a flying start to his bid for a record fourth successive ATP Tour Finals title with a 6-1, 6-1 rout of Japan’s Kei Nishikori, while Roger Federer cruised to a 6-4, 6-2 win against Tomas Berdych on Sunday.

Defending champion Djokovic and six-time winner Federer have dominated the prestigious season-ending event for the last decade, lifting the trophy eight times between them in the last nine years. Djokovic arrived at London’s O2 Arena hoping to win the title for a fifth time and in the process become the first player to lift the trophy four years in a row. The world number one showed why he is the firm favourite to do just that, demolishing Nishikori in 65 minutes to record his 23rd successive win and his 79th victory in 84 matches this year.

With two more group ties remaining against Federer and Berdych, Djokovic’s stroll by the banks of the River Thames was a significant statement of intent to his rivals. “No question I played some of the best tennis I’ve played this year,” Djokovic said.

Meanwhile Federer, the oldest Tour Finals qualifier since Andre Agassi in 2005, is undeniably in the twilight of his career, yet the 34-year-old is still good enough to compete for the sport’s top prizes and is in the hunt for a semi-final berth once again after easing past Berdych in 69 minutes.

To cap an enjoyable day for Federer, he was presented with an award as the fans’ favourite player in 2015 and he said: “I enjoy getting awards, especially the ones that are awarded by the fans. Federer has made a habit of producing landmark achievements at the Tour Finals and, in a testament to his astonishing longevity at the highest level, this was his record 14th straight appearance at an event he has won a record six times in nine final appearances. Berdych initially seemed capable of causing an upset when a pair of Federer double faults contributed to the Swiss being broken in the second game.

But the 17-time Grand Slam winner brushed off that sluggish opening with an immediate response as he hit back in the next game when Berdych slipped on break point. A hard-fought set swung Federer’s way when an error-strewn service game from Berdych gifted him a decisive second break at 4-4. With the first set wrapped up, Federer tightened his grip with another break in the first game of the second set. That effectively ended Berdych’s hopes and Federer cruised to the finish line with one more break.