Serena Williams seeking to win Australian Open for sixth time . Williams ' first opponent in Brisbane will be former world The world No. 1 is aiming to become the first player since Steffi Graf in 1993 and 1994 to complete a Grand Slam singles title at least six times. World No . 1 will begin her new season against Andrea Petkovic . Caroline Wozniacki pulls out of Brisbane event due to injury .
Serena Williams seeking to win Australian Open for sixth time . The world No. 1 is aiming to become the first player since Steffi Graf in 1993 and 1994 to complete a Grand Slam singles title at least six times. World No . 1 will begin her new season against Andrea Petkovic . Caroline Wozniacki pulls out of Brisbane event due to injury .