Sixth-seeded Kei Nishikori was stunned by Polish qualifier Hubert Hurkacz 4-6, 6-4, 6-3 in the third round of the BNP Paribas Open on Tuesday, a big day of upsets in the desert.
On the women's side, world No. 1 and defending champion Naomi Osaka crashed out after she was defeated by Switzerland's Belinda Bencic in a night session on the same court, the 23rd seed claiming a 6-3, 6-1 victory to reach the quarterfinals.
Shortly before 15-time Grand Slam champion Novak Djokovic was beaten in straight sets by 39th-ranked Philipp Kohlschreiber of Germany in Stadium 1, world No. 7 Nishikori was ousted at Indian Wells in another men's singles match at Stadium 2.
"I played well in the first set but my opponent played better from the second set on, making no technical mistakes in serves and strokes. He was aggressive in key situations and I couldn't execute," said Nishikori, who had his left calf taped.
"He's tall and he serves well, but he also plays well defensively. The defense got me today," he said.
In their first head-to-head in last month's Dubai Championships, the Japanese star was sent packing by the 67th-ranked Hurkacz after a shock second-round defeat, also in three sets.
This time in the 2 hour, 4 minute match, Nishikori allowed Hurkacz to convert his third break point chance to take the second set 6-4. In the third set, Nishikori dropped his serve in the sixth game with a double fault and the 22-year-old Pole held his next two service games to close out the match.
Hurkacz, unseeded, reached the fourth round of a Masters 1000 event for the first time in his career. He will meet Canadian teenager Denis Shapovalov in the round of 16.
Later on Tuesday, in their women's singles fourth-round match, top-seeded Osaka was outplayed by Bencic, who captured the title in Dubai, in just over an hour in the match between two players born in 1997.
Osaka struggled on serve and won just 54 percent of her first serves, and was broken in the opening game of the match. Bencic took a 4-1 lead against the back-to-back Grand Slam champion, and broke at 5-3 to take the first set.
Bencic, who broke Osaka's powerful serve five times, raced out to a 3-0 advantage in the second set and kept pouring on the pressure until she scored another big win to extend her season-long winning streak to 11 matches.
Bencic will face fifth-seeded Karolina Pliskova in the quarterfinals.
According to the WTA, Osaka will maintain her hold on the No. 1 ranking through the March 18-31 Miami Open.