Roger Federer got an unexpected day off Friday at the BNP Paribas Open after Nick Kyrgios withdrew from their quarterfinal because of what he suspected was food poisoning.
Less than two hours before they were to take the court, Kyrgios tweeted that he "had a restless night of being sick."
He said "to play a great champion like Roger, I need to be at my best to have a chance."
Kyrgios' withdrawal spoiled the highly anticipated match with Federer. Neither player had dropped serve in the tournament and their only other meeting was decided in three tiebreakers at Madrid in 2015.
"I was really looking forward to playing the match," Federer told fans waiting for the match on stadium court. "It's a pity."
Kyrgios beat No. 2 Novak Djokovic in the fourth round, while Federer routed rival Rafael Nadal.
"I'm playing great tennis and I didn't expect it because I'm still on the comeback," said Federer, who won his record 18th Grand Slam title at the Australian Open in January after being sidelined by various injuries for much of 2016.
Federer, a four-time winner at Indian Wells, also advanced via a walkover in the quarterfinals in 2008.
He next faces No. 4 Kei Nishikori or 17th-seeded Jack Sock, who played their quarterfinal later Friday.
Scrambling to find something for fans to watch, tournament officials trotted out tournament director-player Tommy Haas and Vasek Pospisil for an exhibition. Pospisil upset top-ranked Andy Murray in the second round before losing to Dusan Lajovic in his next match.
The women's semifinals on Friday featured No. 14 Elena Vesnina against 28th-seeded Kristina Mladenovic and No. 3 Karolina Pliskova against No. 8 Svetlana Kuznetsova.
Top-ranked Serena Williams withdrew before the tournament began with what she said was a knee injury that will also keep her out of the Miami event next week.