Tennis-Serena overpowers Azarenka to reach semi-finals

LONDON, July 7 (Reuters) - Top seed Serena Williams overpowered Victoria Azarenka in an absorbing Wimbledon quarter-final on Tuesday, recovering from a set down to win 3-6 6-2 6-3. The American, who will face Russia's Maria Sharapova in the semi-finals, is two wins away from holding all four grand slam titles concurrently -- the so-called Serena Slam she also achieved in 2002-03. The 33-year-old was second best in the first set against the Belarussian former world number one on Centre Court, but she found an extra gear and dominated thereafter. Three consecutive aces at 4-2 in the third set moved her to within a game of victory and although 23rd seed Azarenka hung on and threatened to break back, Williams would not be denied and stayed on course for a 21st grand slam title. "It was fun out there and I saw Victoria smiling as well, we both really enjoyed it," five-times Wimbledon champion Williams, who has won 26 grand slam matches in a row, said in a TV interview. (Reporting by Martyn Herman; editing by Ken Ferris)