World number one Serena Williams has admitted that she was not a 'robot' and couldn't win every match she played after losing to Angelique Kerber in the Australian Open women's singles final on Saturday.
The German seventh seed claimed a 6-4, 3-6, 6-4 win over defending champion Serena in a enthralling summit clash that lasted two hours and eight minutes at Rod's Laver Arena.
The 28-year-old power-hitting southpaw also denied Serena a chance to win a seventh Melbourne singles title, and to match German great Steffi Graf's 22 Grand Slams record.
Congratulating Kerber on her maiden Grand Slam win, Serena said that she was inspired by the German's never-give up attitude with which she had played, News.com.au reported.
The American insisted that the stunning defeat would spur her for the upcoming season, adding that she would be required to display her best performance to win big tournaments.
Serena, who produced an error-strewn performance with 46 unforced errors, also conceded that Kerber was tactically superior to her.