<Tr> <Td> ← 2017 </Td> <Td> Australian Open </Td> <Td> 2019 → </Td> </Tr> <P> Serena Williams was the defending champion, but chose not to participate this year, stating that she was not fully fit after giving birth to her daughter in September 2017 . </P> <P> Caroline Wozniacki became the first Danish player to win a Grand Slam singles title, defeating Simona Halep in the final, 7--6, 3--6, 6--4 . Wozniacki also regained the WTA no . 1 singles ranking for the first time since 2012 . Both finalists saved match points earlier in the tournament: Halep saved three match points against Lauren Davis in the third round and two match points against Angelique Kerber in the semifinals, while Wozniacki saved two match points against Jana Fett in the second round . </P> <P> In addition to Wozniacki and Halep, Garbiñe Muguruza, Elina Svitolina, Karolína Plíšková and Jeļena Ostapenko were also in contention for the no . 1 singles ranking at the start of the tournament . </P>

Who won women's singles australian open 2018