Injured No. 1 Serena Williams follows Azarenka in quitting Dubai

Serena Williams delivers an on court interview as she withdraws from her match on the third day of the Dubai event.

Story highlights

  • Serena Williams pulls out minutes before scheduled clash with Marion Bartoli
  • World No. 1 says back problem has troubled her for the past fortnight
  • American targets next month's Sony Ericsson Open in Miami for comeback

Hours after losing Victoria Azarenka to injury, organizers of the Dubai Tennis Championships were dealt another major blow on Wednesday when Serena Williams also pulled out of the event.

The 31-year-old Williams, who became the oldest women's tennis player to be crowned world No. 1 on Monday, said she was forced out because of a back injury.

"I've just had some back problems the past couple of weeks," the American told an impromptu press conference.

"I thought it would get better as the week went on but it didn't. I don't want to keep pushing it and make it worse."

Read: Serena back on top of the world

Williams took to the court to apologize to fans who had arrived for her second-round match with Marion Bartoli of France.

The absences of both Williams and previous No. 1 Azarenka represent a severe dent to a popular $2 million tournament which had already been without the sport's two reported highest earners, Maria Sharapova and Li Na (according to Forbes magazine).

      Just Watched

      Serena Williams' rise to greatness

    Serena Williams' rise to greatness 07:37
    PLAY VIDEO

      Just Watched

      Tennis: Sloane Stephens stuns Serena

    Tennis: Sloane Stephens stuns Serena 01:08
    PLAY VIDEO

      Just Watched

      Safarova: 'One of my best matches ever'

    Safarova: 'One of my best matches ever' 00:10
    PLAY VIDEO

    It is also a blow to the Women's Tennis Association, which has worked hard to introduce incentives and regulations to reduce the number of withdrawals from its events.

    Wednesday's unexpected withdrawal follows that of second-ranked Azarenka, which ensured that Williams will hang on to top spot until the Sony Ericsson Open, which starts in Miami on March 18.

    Read: Azarenka out of Dubai Open

    Williams said her back also troubled her in last week's Qatar Open, where she was beaten in the final by the Belorussian, who withdrew from the Dubai championships with a foot injury.

    The 15-time grand slam winner added that, having returned to the pinnacle after two and a half years during which her life and career were threatened following a freak foot injury in 2010, being No. 1 is no longer her primary goal.

    "OK, I have done it, let's focus on my next goals which are the grand slams," Williams said, admitting that she already had at least half an eye on the French Open in Paris, starting on May 26.

    "I really want to continue doing really well in those."

    After winning Wimbledon and the US Open last year, Williams' total of grand slam titles is only three fewer than Martina Navratilova and Chris Evert, who together are second on the all-time list behind Steffi Graf with 22.

    Williams' absence increases the chances of world No. 4 Agnieszka Radwanska making a successful defense of her title, which began with the Pole grinding out a 7-, 6-3 win over Yulia Putintseva, a promising 18-year-old wild card entry from Kazakhstan.

    Bartoli, who received a wild-card invite after making a late entry, will face former world No. 1 Caroline Wozniacki in the quarterfinals.

    The Dane, now ranked 10th and a winner of the tournament in 2011, progressed with a 6-0 6-1 drubbing of China's former Wimbledon semifinalist Zheng Jie.

    .

        Tennis

      • Rafael Nadal of Spain watches the ball in his match against Martin Klizan of Slovakia during during day seven of the China Open at the National Tennis Center on October 3, 2014 in Beijing, China.

        Rafael Nadal's body might be giving him a few problems, but his mind remains as strong as ever. Will the Spaniard add to his haul of 14 grand slam titles?
      • LONDON, ENGLAND - OCTOBER 17: Wimbledon champion Andy Murray and his long time girlfriend Kim Sears arrive at Buckingham Palace on October 17, in London, England. Murray will become an Officer of the Order of the British Empire (OBE) and receive his medal from the Duke of Cambridge. (Photo by John Stillwell - WPA Pool/Getty Images)

        The Scot has served up a few changes to his support team in 2014 but there's one person who isn't going anywhere -- his new fiancée Kim Sears.
      • Despite being forced to retire at the age of 24 due to health problems, Lacoste remained in the game and went on start the "Lacoste" brand in 1933, which specialised in tennis products. The inspiration for the company's logo came from his nickname as a player, "le crocodile."

        His distinctive crocodile logo is seen on clothing all over the world, but Rene Lacoste also left a lasting legacy in the development of tennis.
      • Serena Williams of the US holds the US Open trophy after defeating Caroline Wozniacki of Denmark during their US Open 2014 women's singles finals match at the USTA Billie Jean King National Center September 7, 2014 in New York. AFP PHOTO/Stan HONDA (Photo credit should read STAN HONDA/AFP/Getty Images)

        Serena Williams is without peer in the modern women's game and now she is on a par with two American tennis legends from the past.
      • American tennis player and golfer Althea Gibson (right) receives a kiss from compatriot Darlene Hard, whom she beat in two sets to become the first black woman to win the Women's Singles Finals at Wimbledon.

        Over the course of her remarkable life, Althea Gibson was many things to many people -- but it was tennis where she really left her mark.
      • "I didn't cry once when I practiced in front of the mirror," says Martin Emmrich. But the nerves kicked in when he got down on one knee on court.
      • LONDON, UNITED KINGDOM - JULY 03: Tennis / Frauen: Wimbledon 2004, London; Finale; Siegerin Maria SHARAPOVA / RUS 03.07.04. (Photo by Bongarts/Bongarts/Getty Images)

        It's 10 years since a teenage Maria Sharapova became the darling of Wimbledon's hallowed Center Court, launching herself as a star.
      • Five-time grand slam champion Martina Hingis has followed her mom into a coaching role, setting up a new tennis academy in Barcelona, Spain.