- Defending champion Roger Federer wins opening match at Swiss Indoors event
- Federer beats late replacement Benjamin Becker to reach second round
- Swiss star is battling with Novak Djokovic for year-end No. 1 ranking
- Women's season-ending tournament will start in Istanbul on Tuesday
Roger Federer is looking to the comforts of home as he continues his bid to hold the year-end world No. 1 ranking for the first time since 2009.
The Swiss tennis star needs to defend his title in Basel to avoid dropping points in the run-up to the season-ending finals in London next month, with Novak Djokovic seeking to regain his place at the top.
"It is just so great to play at home as world number one after the season I've had," the 31-year-old told reporters following Monday's first-round win over Benjamin Becker at the Swiss Indoors hard-court event.
"It's a wonderful feeling to be here playing at the top of my game. Sometimes things just all come together."
Federer, playing for the first time since losing to Andy Murray in the Shanghai semifinals earlier this month, won 7-5 6-3 against the 83rd-ranked German -- a late replacement for injured Frenchman Jeremy Chardy.
"He broke me at 2-3 but I was able to get it straight back. It all went so fast at the end, but the first set was really tough," said Federer, who has won the Basel title five times and been runner-up on three occasions in 12 previous appearances.
The Wimbledon champion now has more than 300 career weeks at No. 1 -- the first man to do so -- but faces a difficult task to hold off second-ranked Djokovic, who won the Shanghai title and has the chance of picking up more points due to his lackluster end to 2011.
The Serbian has taken this week off ahead of the men's season's penultimate event, the Paris Masters -- which Federer also won last year before triumphing in the ATP Tour World Finals.
With U.S. Open champion Murray pulling out of Basel for the second year in a row, this time due to a back problem, Federer faces a relatively weak field.
The London 2012 silver medalist next takes on either Brazil's Thomaz Bellucci or Japan's Go Soeda, and would not play a top-10 player until the final should his 2009 U.S. Open conqueror Juan Martin del Potro make it that far.
The eighth-ranked Argentine won this month's event in Vienna in his first singles tournament since September's U.S. Open, having suffered a recurrence of his wrist injury during the Davis Cup semifinal against the Czech Republic.
Meanwhile, Tomas Berdych -- who led the Czechs into the November 16-18 final against Spain -- has become the sixth player to qualify for the eight-man season-ending event in London.
Berdych, who won his eighth career title in Stockholm on Sunday, follows Djokovic, Federer, Murray, David Ferrer and Rafael Nadal -- who is unlikely to take his place at the showpiece event due to his knee injury.
Meanwhile, the women's season-ending WTA Championships start on Tuesday in Turkey, with Maria Sharapova beginning her bid to wrest the No. 1 ranking from Victoria Azarenka.
The Russian will take on Italy's Sara Errani in a repeat of June's French Open final, which Sharapova won, while defending champion Petra Kvitova will launch the tournament against Agnieszka Radwanska in the other Group B match.
"Unfortunately last year I was a bit injured and wasn't able to play 100%, so it's nice coming in this year knowing I'm ready,"said Sharapova.
Third-ranked Serena Williams, who cannot topple Azarenka despite her victories at Wimbledon, the Olympics and the U.S. Open, will play Germany's Angelique Kerber in Tuesday's other match.
U.S. Open finalist Azarenka, also in Group A along with China's Li Na, needs to win two matches to seal the year-end No. 1 spot.
The Belorussian has won her past two tournaments following a surprise defeat by Kerber in the Tokyo quarterfinals.