MELBOURNE (Reuters) - Reigning champion Serena Williams ramped up the power to beat fifth seed Maria Sharapova for the 18th match in a row and reach the semi-finals of the Australian Open 6-4 6-1 on Tuesday.
Russian Sharapova broke the world number one in the first game and mounted a stiff challenge in the opening set but wilted in the second to extend a losing record against Williams that goes back 12 years.
The 34-year-old American, who twice had treatment during breaks in the rematch of last year's final, has reached the last four at Melbourne Park on six previous occasions and gone on to win the title every time.
Williams, who is looking for her 22nd major singles title, has a 8-0 head-to-head record against her semi-final opponent Agnieszka Radwanska.
(Reporting by Nick Mulvenney; Editing by John O'Brien)