Swiss seventh seed Belinda Bencic was stunned by Slovakia's Magdalena Rybarikova while former champion Ana Ivanovic was also sent packing in third-round action at the BNP Paribas Open in California on Monday.
The 97th-ranked Rybarikova, who eliminated 31st seed Daria Gavrilova in her previous match, got by the powerful Bencic 6-4, 3-6, 6-3 while Czech Karolina Pliskova dumped former Serbian world number one Ivanovic 6-2, 6-0 in a fleeting 49 minutes.
After an uneven start at the Indian Wells Tennis Garden, 18th seed Pliskova's game clicked into gear in spectacular fashion, reeling off 10 consecutive games to close out her one-sided victory.
Ivanovic entered the tournament fresh off a run to the quarter-finals and semi-finals in Dubai and St. Petersburg, respectively, while Pliskova had suffered a couple of early exits in the Middle East.
Pliskova, perhaps, perked up in seeing Ivanovic across the net. She had won all three of her previous encounters with Ivanovic, including earlier this year in Sydney.
"We've played a few times already and I've always won. But I think I played really good tennis today and I'm happy that I made (the next round) so fast," said Pliskova, who powered in 18 winners.
Next up for Pliskova will be Britain's Johanna Konta, who advanced 6-4, 6-1 over Czech Denisa Allertova, who had conquered second-seeded Australian Open champion Angelique Kerber in the previous round.
Rybarikova advanced to another challenging test against US Open runner-up Roberta Vinci.
The ninth-seeded Italian hurried past Elina Svitolina of Ukraine 6-1, 6-3 to book her spot in the fourth round.
Second seed Murray ousted by Delbonis
World No 2 Andy Murray squandered a 4-1 lead in the third set before losing a tiebreaker to Argentine left-hander Federico Delbonis and exiting the BNP Paribas Open third round 6-4, 4-6, 7-6(3) in California on Monday.
The second-seeded Scotsman let his commanding lead evaporate on a warm, windy day at Indian Wells and needed to break the 53rd-ranked Delbonis in the 12th game just to force the tiebreaker, which the Argentine won 7-3.
Delbonis took advantage of a series of Murray errors to run off the last five points of the decider to end the two hour, 46 minute struggle in Stadium 1.
"Thanks to everybody here for such an amazing match. It was a very intense match, very passionate, I think," the Argentine said.
Delbonis, who reached quarter-finals this year in Rio and Sao Paulo, varied his strategy against Murray and took advantage of some weakness in the Scot's serve. Murray failed to register a single ace and won less than 50 percent of his second serves.
"I know it was a challenge," said Delbonis. "I have to mix (my shots) all the time.
"In the end, I can do my job and this is what I get."
It was a short appearance in only the second tournament of the year for Murray, who lost in the final of the Australian Open to world number one Novak Djokovic.
In another day match, 12th seed Milos Raonic of Canada advanced to the fourth round 6-3, 3-0 when Australian Bernard Tomic retired in the second set.
Tomic had complained about an injured wrist before the match against the hard-serving Raonic.