Radionova made her senior international debut at the 2013 Nebelhorn Trophy. Placing first in both programs, she won the gold medal by a margin of more than 25 points over two-time world champion Miki Ando from Japan. The 2013 Skate America was Radionova's first senior Grand Prix event. She was awarded the bronze medal at Skate America and then silver at the 2013 NHK Trophy, while gold at both events went to Japan's Mao Asada, whose skating Radionova admires. Radionova's results qualified her to her first Grand Prix Final. At the event in Fukuoka, Japan, she finished fourth overall.