American Lilly King has her sights set on winning Olympic gold and she’s not about to let anyone get in her way, especially not world champion breaststroker Yulia Efimova of Russia. King made that clear in a finger-waving display worthy of Dikembe Mutombo as she disparaged the Russian for doping.

Efimova is being allowed to compete at the Rio de Janeiro Games following a 16-month suspension for doping and despite another positive test this year for the now-banned substance meldonium. The 24-year-old Russian is a flashpoint in her country’s doping scandal because of her two infractions.

When Efimova waved a No. 1 finger after her semifinal on Sunday, King leaned back and gave her own version toward Efimova’s face on a TV monitor. King then qualified fastest for the eight-woman final in 1 minute, 5.70 seconds, just ahead of Efimova’s time of 1:05.72.

The two women square off in the 100-meter breaststroke final tonight, swimming next to each other.

Efimova’s positive test for meldonium was placed on hold while world anti-doping officials conduct further studies on the drug.

“If that’s what she feels she needs to be able to compete, whatever, that’s her deal,” King told reporters. “I’m here to compete clean for the U.S. and that’s what I’m going to do.”

A smattering of boos greeted Efimova after she won her preliminary heat Sunday. The Russian men’s 4×100 freestyle relay was also booed when introduced for their final the same night.

Ruta Meilutyte of Lithuania, the world record holder in the 100 breast, said Efimova’s doping history is disrespectful to other athletes.

“We train fair,” she said. “When something like that happens, it’s never nice. These are not the values of our sport.”

Kirsty Coventry of Zimbabwe, a seven-time Olympic swimming medalist competing in Rio, serves on the International Olympic Committee’s athletes’ commission.

“Hopefully, that ban made her clean in a way,” she said of Efimova. “Hopefully, people that are cheating now know that they’re going to get caught. It’s just a matter of time. It’s a little disappointing that there are certain people that are here.”