American swimmer Lilly King was not in a medal race Sunday night, but she drew a greater post-race reaction than anyone who won gold, silver or bronze.

That's because after King placed first in the semifinals of the women's 100-meter breaststroke with a time of 1:05.70, she wasted no time calling out her steepest competition for the gold medal in Monday's final.

First, the back story. Yulia Efimova of Russia is arguably the favorite to win the 100m breaststroke, but many believe she should not even be competing in the event.

Efimova was one of seven Russians banned from the 2016 Rio Olympics by the International Swimming Federation in response to the doping scandal involving the country. This came after she had just finished a year-plus suspension for doping and had another more recent failed test overturned.

Somehow, Efimova was eventually reinstated for the Olympics, which obviously angers her peers.

Fans in Rio De Janeiro have even gone so far as to boo Efimova in both her preliminary race and semifinal -- as they have most Russian swimmers in these Summer Games. Still, Efimova finished her semifinal in 1:05.72, first in her heat and eventually second overall.

Back to the present. King, watching Efimova celebrate her first-place finish in her semifinal heat, mocked the Russian swimmer by wagging a finger of disapproval at a television while Efimova held up the "No. 1" sign in the pool.

King then went out and beat Efimova's time by two-hundredths of a second.

After placing first in her heat and the semifinals as a whole, King was interviewed by NBC and asked specifically about her finger wag from minutes earlier and what was going through her head at the time.

This is where she slayed Efimova and probably further hindered U.S.-Russian relations.

"You're shaking your finger No. 1, and you've been caught for drug cheating. I'm just not a fan," she said.

Boom.

Americans watching live on TV lost it and took to Twitter to crown King the smack talk queen. Hopefully she can follow that up by bringing home the gold on Monday.

It's on.