Pan American Games welterweight champion Oshae Jones was victorious in her first bout here at the International Boxing Association (AIBA) Women's World Championships.
The boxer from the United States unanimously defeated Ani Hovsepyan of Armenia to progress, but faces a tough challenge next.
She will come up against Rio 2016 Olympic bronze medallist Dariga Shakimova of Kazakhstan, who recorded a unanimous victory against Czech Martina Schmoranzová.
There was an upset in the bout between England's Commonwealth welterweight champion Sandy Ryan and Ireland's Christina Desmond, with the latter triumphing 4-1.
Yang Liu then stunned the division's seventh seed and former European champion, Elina Gustafsson of Finland, receiving a unanimous decision.
The Chinese boxer's next opponent will be Rosie Eccles of Wales, with the Commonwealth silver medallist beating Lucia Perez of Argentina 5-0.
Saadat Dalgaatova of Russia was the unanimous winner against Erdenetuya Enkhbaatar of Mongolia, delighting the substantial home crowd.
A handful of lightweight bouts took place, including one involving Russian captain Natalia Shadrina.
Shadrina, who hails from the host city, got past Imane Khelif of Algeria 4-1.
Commonwealth Games lightweight champion, Anja Stridsman of Australia, was then the unanimous victor against Japan's Tomoko Kugimiya.
Boxers in the bantamweight division also began their World Championships campaign, with Italian Giordana Sorrentino defeating Saya Hamamoto of Japan unanimously.
Another unanimous result went to India's Jamuna Boro against Erdenedalai Michidmaa of Mongolia, while Antonia Konstantopoulou of Australia edged past Iulia Coroli of Moldova 3-2.
Competition continues tomorrow in the featherweight and middleweight divisions.