World No4 Simona Halep became the first major casualty of the Australian Open after crashing out in the opening round following defeat to American Shelby Rogers.
For the second successive year Romania’s Halep stumbled at the first hurdle of the season-commencing grand slam, losing 6-3, 6-1 to power-hitting Rogers, herself a first-round loser in her only previous Australian Open appearance in 2015.
Halep, seeded fourth at Melbourne Park, cited a nagging knee injury which she has been battling since the WTA Finals in Singapore in October for her demise, having sought medical attention after the first set.
“I can play about 45, 50 minutes without pain and then it comes,” said Halep. “Today it was about 5-3 in the first set, so then it was tough to fight and I couldn’t do what I wanted.
“I probably need some time off to get it well, recovered, because it’s difficult to play with the pain and the knees are dangerous.”
Defending champion Angelique Kerber, meanwhile, began her quest to retain her Australian Open crown with a laborious victory over Lesia Tsurenko of Ukraine on Rod Laver Arena.
World No1 Kerber dropped a set after Tsurenko saved a match point in the second and forced a decider, only for Kerber to draw on her experience and prevail 6-2, 5-7, 6-2. The 28-year-old will face fellow German Carina Witthoeft in round two.
“I won the match and that’s what counts,” said Kerber. “The first round is always tough. I’m so happy to be in the second round. I’m really happy to be back here. Everything started here for me when I won my first grand slam here.”
Seven-time grand slam champion Venus Williams also progressed after edging past Kateryna Kozlova 7-6 (7-5), 7-5, while French Open winner Garbine Muguruza dispatched New Zealand’s Marina Erakovic 7-5, 6-4.