( CNN ) -- Roger Federer may have given up his No . 1 ranking , but the Swiss tennis star 's grip on end-of-season supremacy is showing no signs of loosening . Federer marched into the semifinals of the $ 5.5 million ATP World Tour Finals on Thursday , beating in-form Spaniard David Ferrer 6-4 7-6 ( 7-5 ) for his second successive straight-sets win in Group B . The 31-year-old has not lost at the eight-man London showpiece since 2009 , and has now won 70 matches this year -- a feat he had not achieved since 2006 when he was at the peak of his powers . `` This is a very special tournament in many ways , '' said Federer , who has reached the last four in 10 of his 11 appearances . `` It 's always been the tournament I wanted to be part of when I started playing at the beginning of the year , many years now . I had breakthrough results at this event . I learned a lot . `` I 've loved everywhere I 've played over the years at the World Tour Finals . But I think this one is obviously special , because it 's in London and The O2 is an amazing venue . I 'm happy it 's going to stay here for the next few years . '' The 17-time grand slam champion relinquished the year-end top spot to Novak Djokovic when he decided not to defend his Paris title last week , having pushed his record tally to 302 weeks at the top . Fifth-ranked Ferrer took advantage of a weakened field and shock defeats for Djokovic and No . 3 Andy Murray by winning his first Masters level tournament , following up his title in Valencia . However , the 30-year-old had never beaten Federer in 13 previous attempts , winning just three of 30 sets played -- including defeat to Federer in the 2007 final of the elite event when it was held in Shanghai . That run continued on Thursday after Ferrer failed to covert three break points on Federer 's serve in the opening game . Djokovic edges Murray at ATP finals . `` It was a long match and I 'm extremely happy to win , '' Federer said after ending Ferrer 's 11-match unbeaten run . `` I played a great match . I 've qualified and I 'm obviously relieved and thrilled that that 's the case . `` David 's been on a great run and he is so respected by his fellow competitors . I enjoy playing against him , not because I 've got a good record , but because he 's a great guy and a great competitor . '' Federer now has a 102-1 record against players aged over 30 since his 2002 defeat by Andre Agassi in the final of the Miami Masters . If he retains his title , extending his record to seven overall in the indoor hard-court event , he will match third-placed John McEnroe on the ATP 's career title list with 77 . Ferrer has won an ATP Tour-leading 73 matches this year , one more than Djokovic -- who will seek to clinch his semi spot in his third and final closing Group A match against sixth-ranked Czech Tomas Berdych on Friday . Ferrer , who also has a tour-leading seven titles in 2012 , must now beat Janko Tipsarevic if he is to emulate last year 's achievement of reaching the semifinals in London . `` I had a lot of chances to break his serve , '' Ferrer said of his latest Federer defeat . `` When he had one break point , he made it . `` Sometimes with these players , if I do n't take my chances , I do n't win the important points -- it is very difficult to win . '' Ferrer is fighting for a semifinal place with Juan Martin del Potro , who beat Tipsarevic 6-0 6-4 in Thursday 's late match to end the Serbian 's hopes . The Argentine now also has one win and a defeat ahead of his final match against Federer , but has the advantage over Ferrer in sets and games won . Del Potro beat Federer in last month 's Basel final but has a losing 13-3 record against him despite notable victories in the 2009 U.S. Open title match and in the round-robin stage of that year 's ATP finals .
Roger Federer extends his winning run to 12 matches with win over David Ferrer . World No . 2 qualifies for semifinals at ATP 's season-ending event for 10th time . He ends Paris and Valencia champion Ferrer 's 11-match unbeaten run . Spaniard must now beat Janko Tipsarevic to have chance of going through .