* Azarenka comes from a set down to advance
* Extends winning streak for season to 16-0
* Kerber beats Wickmayer 6-1 7-6 (Adds further Azarenka quotes)
INDIAN WELLS, California, March 11 (Reuters) - Australian Open champion Victoria Azarenka struggled to find her rhythm against Kirsten Flipkens in the third round of the BNP Paribas Open on Monday but finished strong to beat the Belgian 3-6 6-3 6-0.
After the wayward start, the top seed and defending champion stormed through the final set, breaking her opponent's serve in the first, third and fifth games before serving out for victory when a Flipkens backhand flew long.
"Kirsten showed some incredible tennis and I did not play very well in the beginning," Azarenka said courtside after improving her record this season to 16-0. "I just couldn't get into a rhythm.
"I wasn't feeling very well today ... I just wanted to go to sleep instead of playing tennis," the 23-year-old later told reporters. "I couldn't breathe, and I was too stupid ... to use a tissue.
"But she really played well. I have to give her credit. She came out firing, playing so freely and going for every possible shot there was. I just didn't adjust well."
Asked how she had managed to rebound from her poor start, Azarenka replied: "I just blew out my nose, started breathing better, calmed down and started to see what I had to do, because before that I was kind of blinded."
The Belarusian is bidding to become the first woman to successfully defend the WTA title at Indian Wells since Martina Navratilova in 1991.
Azarenka, who demolished Russian Maria Sharapova 6-2 6-3 in last year's final, will next face Poland's Urszula Radwanska, who earlier overcame American Jamie Hampton 6-0 7-6 at the Indian Wells Tennis Garden.
Fourth seed Angelique Kerber also advanced, heeding the advice of her coach to come from 1-4 down in the final set to beat Belgian Yanina Wickmayer 6-1 7-6.
Told to rely on self-belief while concentrating on the strategy they had mapped out before the match, the German left-hander won five of the next seven games before clinching the tiebreak 7-4 on a hot morning.
Kerber, a semi-finalist here last year when she lost to eventual champion Azarenka, will next meet Spaniard Garbine Muguruza Blanco, who swept past Slovakia's Magdalena Rybarikova 6-4 6-0.
"Last time it was very tough so I knew it wasn't going to be easy today," said Kerber, who needed three sets to beat Wickmayer in their previous meeting.
"At 1-4, my coach came on court and told me to remember the game plan. He said, 'Just focus on your game, believe in yourself,' and I did it. I'm just happy to be in the next round."
The German world number six broke Wickmayer three times to breeze through the opening set in 31 minutes but then lost her way and failed to hold in her next three service games.
In all, there were eight breaks of serve in an erratic second set as the Belgian delivered a mix of crunching forehand winners with a series of unforced errors.
After Kerber leveled at 6-6, she dominated the tiebreak and sealed victory after one hour 22 minutes with a forehand winner down the line that left Wickmayer stranded at the net.
"After my coach spoke to me, I was just playing point by point, and believing in my game," said Kerber, who was forced to withdraw from a Fed Cup match against France last month due to a back injury.
"His advice certainly helped. Before the tournament I was not sure how my back will feel after matches. Now my confidence is of course back and I feel good. I'm looking forward to play tomorrow again."
In other matches, seventh seed Samantha Stosur of Australia overcame China's Peng Shuai 6-3 3-6 6-2, eighth-seeded Dane Caroline Wozniacki crushed Russian Elena Vesnina 6-2 6-1 and 10th-seeded Russian Nadia Petrova pummeled Germany's Julia Goerges 6-1 6-2. (Reporting by Mark Lamport-Stokes; Editing by Frank Pingue/Peter Rutherford)