Roger Federer
Federer barely broke sweat to mark his first match of the finals with a win.Getty Images

Roger Federer produced a gritty performance to see off the challenge of Tomas Berdych and begin his pursuit of a record seventh ATP World Tour Finals title with a two-set win at the O2 Arena in London. The 34-year-old clinched the 6-4 6-2 victory in just 69 minutes to set up a meeting with world number one and three-time defending champion Novak Djokovic on Tuesday [17 November] in an early round robin clash.

Federer, who withdrew from last year's final due to a back injury, goes into that clash with Djokovic after a showing which began on the backfoot, but ended with a flourish against Berdych - who was unable to follow up Czech Republic's Fed Cup victory over Russia and already faces an uphill task to reach the knock-out phase. The former Wimbledon runner-up takes on Kei Nishikori in his second match; a must win for both players if they have any designs on reaching the semi-final.

Having seen three-time defending champion Djokovic begin his campaign with seamless victory over Nishikori for the loss of just two games, fellow group rival Federer was keen to lay down a similarly signficant marker. That task would seemingly be made all the easier against a player in Berdych who had won just six matches in five appearances at the season-ending tour finals and had gone 32 months since his last victory over the 17-time grand slam champion.

The firm underdog would start with the greater fizz on his ground-strokes but soon his forehand and serving would desert him. An early 2-0 lead was quickly gobbled up by Federer though, to square the opening set, though it could have been better for the Swiss had he taken one of two break-point opportunities in game five.

Berdych's serve and power, coupled with Federer's shakiness, ensured he had a foothold in every game but his inability to effectively turn defence into attack left him open to failure. A string of errors triggered by a netted forehand volley gave Federer a second break and eventually the first set following a faultless service game.

The manner in which Berdych allowed the set to slip through his grasp was compounded when the Czech allowed himself to be broken at the start of the second set, to leave the writing very much on the wall. Federer had won their two meetings in 2015 in emphatic fashion and was threatening to produce a similarly convincing victory to begin his tour finals assault.

Federer grabbed the double-break as Berdych began to struggle to control the pace and direction of his groundstrokes at the baseline, and as victory edged closer the former world number one produced a spate of virtuoso drop shots which had his opponent reeling. The win was secure after just over an hour but bigger challenges are to come for Federer, starting against the number one seed.