Russian swimmer Yulia Efimova surfaced after winning the first semifinal heat in the women’s 100-meter breaststroke Sunday night in Rio and raised a finger in celebration.

American swimmer Lilly King’s response? Pure gold.

Upon seeing Efimova’s gesture on-screen in the ready room before hitting the water in the second semifinal, the 19-year-old King gave the Russian a disapproving, Dikembe Mutombo-esque finger wag.

“You know, you’re shaking your finger ‘No. 1’ and you’ve been caught for drug cheating, I’m just not — you know, I’m not a fan,” King said on NBC.

A fired-up King then swam the fastest time of the semifinals, touching the wall in 1 minute, 5.70 seconds, edging Efimova’s time of 1:05.72.


Efimova, the bronze medalist in the 200-meter breaststroke in London, tested positive for a banned substance in 2014 and served a 16-month suspension. She failed another drug test in March 2016 and was initially banned from competing in Rio along with more than 100 other Russian athletes. The ban was later overturned by the International Olympic Committee.

Olympics organizers are urging competitors to cut the trash talk. International Olympic Committee spokesman Mark Adams says ‘‘people should be free to compete in tranquility and not be addressed by others. We would encourage people to respect their fellow competitors.’’

A smattering of boos greeted Efimova after she won her preliminary heat.

At an IOC briefing, Adams said: ‘‘Brazilian fans seem to be pretty egalitarian. They seem to boo athletes from many countries. It’s quite difficult to work out why they might be booing one athlete and not another.’’

King and Efimova will face off in the 100-meter breaststroke final on Monday night.

“Gonna go out swim my heart out for USA and hopefully that turns out the best,” King said.

Yulia Efimova raised a finger celebrating her heat win on Sunday.
Yulia Efimova raised a finger celebrating her heat win on Sunday.Dave Hunt/EPA

Material from the Associated Press was used in this report. Emily McCarthy can be reached at emily.mccarthy@globe.com. Follow her on Twitter @emilymccahthy.