MELBOURNE, Jan 15 (Reuters) - World number one Victoria Azarenka got her Australian Open title defence underway with an unconvincing 6-1 6-4 victory over Romania's Monica Niculescu on Rod Laver Arena on Tuesday.
The Belarusian did well to battle back to secure victory without going to a third set after going 3-0 down in the second, but the way her first serve fell apart at times will only encourage her main rivals for the crown.
Second seed Maria Sharapova got her campaign off to a blistering start without losing a game on Monday and third seed Serena Williams followed suit with a similarly convincing win despite a tumble on Hisense Arena on Tuesday.
Azarenka will perhaps reassure herself that she will be more battle-hardened after her 87-minute win over Niculescu as she prepares for a second-round tie against Eleni Daniilidou or Karolina Pliskova. (Reporting by Nick Mulvenney, editing by Peter Rutherford)