Nicole Auerbach

USA TODAY Sports

RIO DE JANEIRO — American Lilly King beat Russian Yuliya Efimova in the most anticipated finale of the day, one set up by a war of finger wagging and some sharp words a day earlier.

King won in 1:04.93, an Olympic record, beating Efimova by .57. American Katie Meili won bronze.

The suddenly heated rivalry began, really, with Efimova’s arrival here. Having been caught twice using banned substances, Efimova became the poster child for the IOC’s lax handling of the Russian systemic doping scandal to which she was linked — an athlete who had failed multiple drug tests and was still, inexplicably, allowed to compete for an Olympic medal. FINA has not returned USA TODAY Sports’ request for comment regarding the reasoning behind her inclusion.

Brennan: Lilly King makes a pointed statement against Russian doping

“I don’t know what to do,” Efimova said after her preliminary heat on Sunday. “It was crazy the last year and a half. I didn’t understand what was going on. I’m just happy to be here and ready to race.”

Efimova, who did not speak to the media after her semifinal swim, served a 16-month suspension for doping from late 2013 to February 2015 and also failed a test for meldonium earlier this year (only for the result to be later overturned).

None of that sat well with King, the 19-year-old American competing in her first Games. It didn’t sit well with the crowd, either, which heartily booed Efimova each time her name was announced and each time she swam here this week.

King mocked Efimova with a finger wag prior to her semifinal swim after Efimova shook her finger after her own heat. King then openly questioned why Efimova was allowed to compete here, saying she didn’t agree with the decision, and added that she’s not a fan of anyone who cheats.