( CNN ) -- Serena Williams wept with delight after becoming the oldest woman to ever hold the number one world ranking . The 31-year-old American star clinched a 3-6 , 6-3 , 7-5 victory over Petra Kvitova in the quarterfinals of the Qatar Open to move back to the summit following a two-and-a-half year interval which almost saw her quit the sport . `` I am so sensitive nowadays -- I am always crying , but I never thought I would be here again you know , '' Williams told reporters . `` I have been through so much and I never thought I would be here , '' she repeated . Martina : Serena will 'break all records ' Williams first became World No.1 on July 8 , 2002 at the age of 20 and will take top spot for the sixth time her career . It is a remarkable comeback for Williams , who slipped as low as 175 in the rankings after missing almost a year with injury and a life threatening pulmonary embolism in 2011 . But she returned with a bang in 2012 , winning Wimbledon , Olympic Gold , the U.S. Open and the WTA Championships , while she has also triumphed in 59 of her past 62 matches . Williams , who will start her 124th career week at No.1 on Monday , beat Chris Evert 's record of 27 years ago when she reached the top at the age of 30 and 11 months -- six months younger than her successor . Serena Williams hits her own face . That 's a total only bettered by Steffi Graf ( 377 ) , Martina Navratilova ( 332 ) , Evert ( 260 ) , Martina Hingis ( 209 ) and Monica Seles ( 178 ) . The achievement had looked in doubt with Williams 4-1 down in the final set , but the American fought back to clinch a dramatic 7-5 victory . Williams will now face Maria Sharapova in the semifinal after the Russian defeated Australia 's Sam Stosur 6-2 6-4 , while Victoria Azaraenka also progressed to the last four after defeating Sara Errani . Federer breezes into Rotterdam quarters . Meanwhile , defending champion Roger Federer crashed out of the Rotterdam World Tennis tournament after suffering a shock 6-3 7-5 defeat by France 's Julien Benneteau . The World No.2 , who won the tournament in 2005 and 2012 , was hoping to bounce back after losing out at the semifinals of the Australian Open . `` I 'm very disappointed , I have some regrets about this match , '' he told reporters . `` He played great and created more chances than I did . He deserved to win . It was a tough loss , but they do happen . Being broken so many times ( five ) indoors wo n't get the job done . My game was up and down overall . `` He made it difficult and generated pressure . That made you try to serve harder . When I had some chances I did n't take them . I was maybe a point or two away from taking it into a third set and then the clock resets . '' Relaxed Federer accepts the end of his dominance . Benneteau , the world 39 , will play a Saturday a semifinal against either fifth seed compatriot Gilles Simon or Slovak Martin Klizan . `` This was a dream match , and I played like a dream , '' he told reporters . `` This is for sure my biggest win . He was the favorite , but maybe he played a bit tight . I 've been playing well all week , improving with each match . `` I 've had a great week here so far and I hope it 's not finished . '' Second seed Juan Martin del Potro cruised into the semifinals with a victory in straight sets against Finland 's Jarkko Nieminen . The Argentine won 6-3 , 6-4 , and will now face unseeded Bulgarian Grigor Dimitrov who came from a set down to beat Marcos Baghdatis .
Serena Williams will return to the top of the world rankings on Monday . At 31 , Williams is the oldest player to achieve the feat . U.S. star defeated Petra Kvitova in quarterfinals at Wimbledon . Advances to face Maria Sharapova in semifinals .