The Olympic 200m breaststroke bronze medallist stopped the clock at 30.12 seconds to secure victory with a new Universiade record. It was her fourth gold of the competition.
Petra Chokova placed second with a time of 30.99 seconds, while Valentina Artemyeva finished third with 31.39 seconds.
Elsewhere, Italy's women's water polo team beat Canada 6-5 to secure the bronze medal. The final will be contested by Russia and Hungary.
Summer Universiade
Day 10: Hosts Korea power ahead as Walker sprints to 800m gold
13/07/2015 AT 11:00
In volleyball, the Japanese men’s team secured bronze after a 3-0 win over Ukraine. Russia and Poland will battle for gold.
In rugby sevens, the host nation beat South Africa 17-14 to book their place in the final, where they will meet the winner of the other semi-final between France and Great Britain.
In the women's rugby sevens, Italy downed Great Britain to earn the chance to win gold. The Italian side registered a 14-5 win over the Brits, and will now play Russia in the final. Russia booked their place with a 31-5 mauling of Canada.
Russian gymnast Margarita Mamun, just like compatriot Efimova, won her fourth gold medal of the Universiade after claiming victory in the women'sindividual ribbon final.
Mamun's 18.566 points was enough to secure yet another gold, while silver went to Alexandra Merkulova, also of Russia. Miteva of Bulgaria took bronze (17.866).
Earlier, Mamun had won in the individual all-around exercises with hoop and clubs.
Meanwhile, two-times Olympic champion Evgeniya Kanaeva revealed one of the reason behind Russia's success in the gymnastics competition.
"It's great that each of our girls has her own programme, the girls do not repeat others' exercises and perform the very good exercises. Of course, they ask me for advice, but also they give their opinion, we have a very close-knit family," Kanaeva said.
"For sure, I try to see only the good in people, but there are errors, it's a sport, and no errors are allowed here. We hope and support."
South Korean Yongkyu Lim, seeded third, won the men's singles tennis tournament after beating Antso Rakotondramanga from Madagascar in three sets, 6-4 4-6 6-2. Konstantin Kravchuk from Russia and Maxime Quinqueneau from France shared bronze.
London Olympics Greco-Roman wrestling champion Roman Vlasov remains on course to add Universiade gold to his collection after defeating 2012 Olympic silver medallist Arsen Julfalakyan of Armenia in the men's 74 kg.
Victory for Vlasov sees him progress to the semi-finals, where he will meet Belarusian Aliaksandr Dzemyanovich.
Summer Universiade
Day 4: Novoselov brothers win diving gold for Russia
06/07/2015 AT 11:04
Summer Universiade
Games will go ahead despite MERS outbreak, says FISU
17/06/2015 AT 22:19