THERE is a piece of grass in south-west London that belongs to Roger Federer.

He staked another claim to a slice of real estate in the south-east of the capital last night. Federer, the seven-time Wimbledon champion, now bids to be a seven-time winner of the Barclays ATP World Tour Finals after showing his class, resilience and will to defeat Andy Murray 7-6 (7-5), 6-2, in one hour 33 minutes at the 02 Arena in Greenwich.

In tonight's final he will meet world No.1 Novak Djokovic, who beat Juan Martin del Potro 4-6, 6-3, 6-2. The talk in London had been of a new order, of Murray grappling with Djokovic for the big prizes.

Federer, at 31, last night made an unambiguous statement that shouted he is far from being a bystander in any fight for the majors.

The other major noise under the lights of the 02 Arena was the extraordinary support for Federer, that was always boisterous, but strayed into the unseemly with cheers on Murray faults on serve and whistles when he changed a racket.

Federer, of course, was exemplary in his behaviour, overcoming an unsteady start to march confidently into the final before 17,000 spectators.

The first, titanic set lasted more than an hour, with Murray taking first blood, but lying wounded at its end. The Scot came out aggressively, breaking Federer and moving the great champion around the court with clever play. Federer seemed unsure on his backhand and the Scot was also producing serves of up to 136mph.

This unalloyed aggression took Murray to 4-2 and the Swiss player looked much the second best. But, of course, he came back. The brilliance of Federer's game is underpinned by an obduracy, a strength of will that claws him back from desperate situations. He promptly won three games, taking the only break point offered, and the tide of the set turned.

The players rumbled towards a tie break with Murray taking the first advantage, but Federer steadied and took three points from 3-4 to seize the initiative and pull away to win the decider 7-5. It was the world No.2 who made the first breakthrough in the second set, breaking the Scot at 1-1 – with Murray throwing in a mixture of hapless dropshots and a poor backhand – and then winning on serve against a ragged opponent.

The world No.3 held to love to make it 2-3 but Federer won the next two games to serve for the match. The inevitable happened. Federer could not, would not, let Murray off the hook.

A disconsolate Scot said: "I started the match well. He came back in, got the tiebreak. If you watched the game where I got broken from 40-love in the second set, that was down to me hitting three dropshots in that game and missing a regulation backhand in the net. Once he gets ahead, he's incredibly hard to stop. He tends to play better and better when he gets up. I feel like I gave him that advantage at the beginning of the second set."

He could console himself with looking back "on the best year of my career by a mile".

Federer, though, goes on to meet Djokovic, who celebrated his progression into the final by presenting every member of the press with a chocolate as he wandered around the interview room with boxes handed to him by his agent.

"I am really looking forward to it," he said of tonight's final. "Knowing it's the last match of the season, I'm really going to try to give my best physically and mentally to eventually try to get the trophy."

The Serb, who has reached the final of this event for the first time since 2008, has won all four matches he has played in the finals. He said: "I felt a little bit better and fresher physically coming into the tournament than I was in the last two years. I think that is very encouraging, obviously, very positive before you get to play a top player. That was a big difference this year and made me be more prepared for all the matches, and to play a more aggressive style of the game."

The world No.1 has had a draining year, winning the Australian Open in January and now standing one match away from the end-of-season title.

"I look forward to that very much," he said, of the prospect of a holiday. "But right now I need to try to do my best to get ready for the finals. It's the last match of the year, so I'm going to give my best, then have a couple of weeks off."

Del Potro said he was encouraged by the defeat and said his London campaign had strengthened his hopes for next year.

"I beat Roger [Federer] yesterday. I was close to beating Nole today. But in the end, they are too good for me. But I'm getting closer every day."

The Argentinian, who won the US Open in 2009 before being cut down by injury, added: "My big challenge for next year, my big goal, will be to try to fight for the all the grand slams with this top group. You know, those winning all the grand slams: Novak, Federer, Rafa and now Murray. I would like to be part of that."