Indian Wells - Australian Open champion Angelique Kerber, fourth seed Garbine Muguruza and Spanish star Carla Suarez Navarro were all second-round casualties at the Indian Wells hardcourt tennis tournament on Saturday.
World No. 2 and second seed Kerber crashed out of the joint WTA and ATP event, losing her opening match in straight sets 7-5, 7-5 to Czech Denisa Allertova.
Former Wimbledon finalist Muguruza was upset by American Christina McHale 7-5, 6-1 and sixth seeded Suarez Navarro withdrew from the tournament with a right ankle injury just prior to her opening match against Daria Kasatkina.
Kerber knocked off Serena Williams in the Australian Open final in January for the first Grand Slam tournament victory of her career.
But Kerber's biggest problem on the WTA Tour has been inconsistency. She played superbly in Australia but then lost her first match at Doha. This is the third straight year she has lost her opening match at Indian Wells.
"If you lose in the first round you always have the next week to make it better," she said.
"I achieved my goal of winning a Grand Slam. Nobody can take that away from me."
The 28-year-old German said there are now more demands on her time since her victory in Australia.
"The pressure is much different than it was a few months ago," she said. "I will try to learn from this experience. It was a busy week for me. It is a new situation I have to try to get used to."
Kerber said the trophy she won at the Australian Open recently arrived at her home and now sits in the middle of her living room.
"It was a great feeling and it is the highlight of my career right now," she said.
Kerber had no aces and four double faults Saturday. She had her serve broken four times in the 98 minute main stadium match.
"I had my chances in the second set and I didn't take them," she said.
Allertova, 23, advanced to the third round where she will face Great Britain's Johanna Konta.
In other women's matches, seventh seeded Belinda Bencic of Switzerland beat American Laura Davis 6-3, 3-6, 6-3 and Italian Roberta Vinci outlasted Margarita Gasparyan 6-3, 6-7 (7/9), 7-6 (7/5).
On the men's side of the draw, world No. 2 and second seed Andy Murray got his campaign off to a flying start with a 6-4, 7-6 (7/3) win over Spaniard Marcel Granollers.
Murray is playing in his fifth ATP Tour tournament since losing to Novak Djokovic in the final of the Australian Open. It was his fourth championship match loss to Djokovic and the fifth time he has lost in the Australian final.
Murray, who was the Indian Wells runner-up to Rafael Nadal in 2009, advances to the third round where he will face Federico Delbonis who beat Joao Sousa 7-6 (8/6), 6-4.
"I came out and served a good game," Murray said. "I had my service game going, especially in the tiebreaker."
Czech Tomas Berdych defeated Juan Martin del Potro 7-6 (7/4), 6-2 and Canadian 12th seed Milos Raonic routed Inigo Cervantes-Huegun 6-1, 6-3.
Eighth seeded Richard Gasquet beat Nicolas Mahut 6-4, 6-1 in an all-French matchup and Gael Monfils, of France, defeated Pablo Carreno Busta 7-5, 7-6 (7/1).