China's top player Li Na marched into the quarterfinals of the Australian Open on Sunday, defeating the 8th seed Victoria Azarenka in straight sets 6-3, 6-3 in the women's singles fourth round.

The 9th seed converted five of the six break points to seal the victory in one hour and 24 minutes, extending her winning streak to nine matches in the new season, which is the best record of all WTA players.

"I didn't expect it to be easy," said Li, leading 2-1 in their three previous meets. "I lost to her last year, and the other two matches were very tense where I fought to win both in three sets."

"In the previous matches, we switched the control on the court, but today I felt like I am controling all the time," she added, attributing the change to her confidence, especially after beating three-time US Open champion Kim Clijsters in Sydney in the lead-ups to the first Grand Slam of the season.

The 28-year-old claimed her biggest title to date at Sydney last week, where she became the first Chinese player to win a WTA premier singles title.

It is the second time for Li to take a top eight spot at least in Melbourne after finishing at semifinal stage last year.

"This is a dream for me," said Li, referring to a possible first major title here. "I mean, until now I still just follow the dream. I mean, like last year, I need two more steps. So hopefully this year I can do better."

Li will vie for a top four spot with the winner of an upcoming clash between Russian Maria Sharapova and German rising star Andrea Petkovic.