Top seed Victoria Azarenka charged into the fourth round of the Indian Wells WTA tournament by crushing Svetlana Kuznetsova 6-1 6-2 on Sunday, improving her unbeaten record to 19-0 this year.
The Belarusian world number one, who had battled through her opening match against Germany's Mona Barthel 6-4 6-7 7-6, broke Russian Kuznetsova three times in the first set and twice in the second.
Serving for the match at 5-2, Azarenka went 40-15 up before double-faulting but then sealed the win on the next point when her opponent's backhand flew long.
"I'm really pleased with that," a smiling Azarenka told reporters after dispatching Kuznetsova in one hour. "We have practised quite a few times, and I know she's a great player.
"She has so much experience and she's been a grand slam winner, so I knew she was gonna be dangerous.
"I really had to step it up from my last match," she added, referring to her three-hour battle with Barthel on the stadium court in the second round. "I'm glad I could perform much better ... and show some good tennis."
Kuznetsova, who won the 2004 US Open and the 2009 French Open, had won four of their previous meetings but she was outplayed by the Belarusian on a sun-splashed afternoon in the California desert.
Azarenka, who clinched her first grand slam crown at the Australian Open in January, will next meet Germany's Julia Goerges, a 6-3 6-4 winner against Spaniard Anabel Medina Garrigues.
Goerges, who won her second WTA singles title in Stuttgart last year, was eager to take on the game's top player.
"Of course, when you play No. 1 in the world you have nothing to lose," the 23-year-old said. "She's a tough player, she's just recently won a first grand slam and hasn't lost so far a match this year.
"I will just try to focus on my game and play my game, and then I see how far it brings me. It's a tough challenge... but I will be ready for it."
French Open champion Li Na beat fellow Chinese Zheng Jie 6-1 6-3, her first victory over her compatriot in five career meetings.
"It's always tough to play a same-country player because we know each other a lot," said Li, who became the first Asian woman to win a grand slam singles title with her victory over Italian Francesca Schiavone in Paris last year.
"We stay in the national teams so we practise every day and travel all of the time, so it's very tough. But I was so happy because it's the first time I beat her.
"The last meeting was six years ago, so six years can change many things," added Li, who is affectionately known as "Big Sister Na" and "Golden Flower" in China.