Beaten world number one Andy Murray was at a loss to explain his Indian Wells woes after a shock second-round defeat against Canada's Vasek Pospisil.
The Scot's best showing in California came in 2009 as a runner-up to Rafael Nadal and this 6-4 7-6 (7/5) defeat was his first in five meetings against the world number 129.
As such, Indian Wells and Monte Carlo remain the two ATP Tour 1000 events to elude him.
"I don't know exactly why it is, because in practice I normally play pretty well," he said of his struggles in California.
Speaking at his post-match press conference he added: "Some years I've played well. Some years it just hasn't quite happened for me.
"I don't know exactly why that is. I don't know if it's the conditions. I really don't know why I haven't played my best here over the years."
Murray, who claimed his maiden title of 2017 at the Dubai Duty Free Championships last week, was sluggish from the start in the BNP Paribas Open clash.
The 29-year-old was broken four times in total by Pospisil, who celebrated his biggest-ever win on the ATP Tour and declared it as his finest hour.
"He's always played that way, maybe he was doing it better this evening," Murray said of an opponent who needed an hour and 50 minutes to beat him.
"He was maybe a bit more solid from the back, a bit more consistent from the back of the court.
"That allows you and gives you more opportunities to come to the net. If you're making mistakes in the first three, four shots of the rally, it's not easy to come in on the correct ball.
"When you're a little bit more solid, you can be patient and wait for the right shot to come in on."
That moment when you shock the world No. 1... 💪🏼😱
— BNP Paribas Open (@BNPPARIBASOPEN) March 12, 2017
The night belongs to @VasekPospisil 🇨🇦 #BNPPO17 pic.twitter.com/6VVG6JcOEb
In a sign of things to come, Murray was forced to save three break points just to hold his first service game but broke the Canadian in the fourth to lead 3-1.
The Scot saved another break point in the fifth but Pospisil dug deep and eventually converted his fifth opportunity on the Murray serve.
With four match points to play with, the Canadian converted the fourth to secure a place in round three at the expense of the top seed.
"It's an amazing feeling," said Pospisil. "Obviously, it happened pretty quick. I feel like on a comeback trail. I had a tough year last year for many, many different reasons.
"I feel the last couple months I really found my hunger and my motivation to be back on the court training hard again.
"I felt like a big result was coming, because I believe in my abilities, but just kind of had to put the pieces together again.
"Obviously to beat the number one player in the world is incredible. I mean, it's the biggest win of my career, and I'm just thrilled right now."
Jo-Wilfried Tsonga was also dumped out by Fabio Fognini with the Italian winning 7-6 (7/4) 3-6 6-4 in a clash which lasted just shy of two-and-a-half hours.
After winning the first set on a tie-break, Fognini lost the second to seventh-seeded Tsonga but recovered well to win a nervy third.
Stan Wawrinka, seeded third, had an easier time of it by beating Paolo Lorenzi 6-3 6-4 and Gael Monfils also progressed with a 3-6 6-0 6-1 triumph over Barbados' Darian King.
Serbian qualifier Lajovic was a surprise 6-2 4-6 7-6 (7/2) winner against 30th seed Feliciano Lopez of Spain and Ivo Karlovic also suffered a second-round exit to Japan's Yoshihito Nishioka, who triumphed 6-4 6-3.
Pablo Carreno Busta beat Peter Gojowczyk 7-5 6-2 while David Goffin, seeded 11th, was made to work for his 6-4 3-6 6-3 victory over Karen Khachanov.
Tomas Berdych is also safely through to round three after a 7-6 (7/4) 6-4 win against Bjorn Fratangelo while John Isner won two tie-breakers to triumph 7-6 (7/0) 7-6 (8/6) over Mikhail Kukushkin.
There were also second-round wins for Mischa Zverev, Dominic Thiem, Roberto Bautista Agut, Albert Ramos-Vinolas and Pablo Cuevas while Philipp Kohlschreiber benefited from Alexandr Dolgopolov's retirement.
