LOS ANGELES • Serena Williams's first tournament since the Australian Open came to an abrupt end on Sunday, as the ailing 23-time Grand Slam singles champion retired from her third-round match against Garbine Muguruza at the Indian Wells Open.

The Spaniard was leading 6-3, 1-0 when Williams called it a day in the battle of former world No. 1s because of a viral illness.

"Before the match, I did not feel great, and then it just got worse with every second - extreme dizziness and fatigue," the American said in a statement. "By the score, it might have looked like I started well, but I was not feeling at all well physically."

The retirement was the latest setback for the 37-year-old, who has yet to win a title since returning to the WTA Tour last year after childbirth.

This was her second tournament this year following January's Australian Open, where she reached the quarter-finals before bowing out to Czech Karolina Pliskova. Williams' next scheduled event is the Miami Open later this month.

Meanwhile, world No. 2 Simona Halep struggled against Ukrainian qualifier Kateryna Kozlova but prevailed 7-6 (7-3), 7-5.

NYTIMES, AGENCE FRANCE-PRESSE

INDIAN WELLS MASTERS

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