However, there was disappointment for Kavita Chahal who lost her quarterfinal bout to Belarus' Kavaleva Katsiaryna 1:4 in the +81 kg weight category.
Mary Kom, chasing her first world medal in the 51kg division, used her experience to great advantage and defended brilliantly against the Rio Olympic bronze medallist. The third-seed came out with accurate and timely blows to assure India of its first medal in the ongoing championships.
The judges' points at the end stood 29-28, 30-27, 29-28, 30-27, 29-28 in Mary Kom's favour.
"I am quite happy after winning the quarterfinal. I will try my best to do better and get a gold medal," the 36-year-old said after her win over Victor.
She will now face second seed Busenaz Cakiroglu of Turkey on Saturday in the semifinals.
The ace Indian pugilist, who entered the tournament with six golds and a silver in the 48-kg weight category, has now assured herself of at least a bronze medal in 51 kg division.
Mary Kom is now the only boxer, both among female and male, to win eight medals in world championships, thus making her the most successful pugilist in the marquee event.
Apart from eight world medals, her stellar career is also studded with an Olympic bronze medal (2012), five Asian titles, gold medals at the Asian Games and the Commonwealth Games.
( With inputs from IANS )