American Lilly King backed up her trash talk with an Olympic gold medal. (Photo by Adam Pretty/Getty Images)

Words of advice: Don’t get on Lilly King’s bad side.

Not only did she deliver the finger wag seen around the world toward her Russian opponent Yulia Efimova on Sunday night, she followed it up Monday with an Olympic gold medal.

King did so by beating both Efimova, who has tested positive for doping in the past, and the rest of the field in the women’s 100-meter breaststroke final with an Olympic record time of 1 minute 4.93 seconds.

A dejected Efimova, who has been greeted with boos at each of her races in Rio, finished second in 1:05.50, and American Katie Meili won bronze with 1:05.69.

“It’s incredible — winning the gold medal and knowing I did it clean,” King told reporters.

Boom. Roasted.

Asked about the post-race splash in Efimova’s lane, she said, “I think I just floated over that way. I wasn’t actually planning to hit the water in her lane. I just kind of hit the water.”

Sure, if you say so.

King, instead, swam to hug Meili, to whom King said prior to the race: “Our lives are going to change.”

Oh, it has and it will. King had already made the race one of the most anticipated of the Olympic Games and with the victory, fans flocked to social media to praise the brash 19-year-old swimmer from Indiana, who speaks her mind and backs it up in the pool.