The two-time world 500m champion did more than enough to top the qualifiers rankings, which saw 16 skaters progress to Thursday’s quarter-finals.
Canada’s Jessica Hewitt, who raced against Kexin in Heat 7, recorded the second-fastest time of the heats, crossing the line in 43.447 seconds.
Vancouver 2010 bronze medallist, Arianna Fontana of Italy, was among the other qualifiers to catch the eye, winning Heat 6 in 43.568 seconds. She finished narrowly ahead of China’s Li Jianrou, the 2012 overall world champion.
Meanwhile, Marianne St-Gelais (CAN), who took the silver in Vancouver four years ago, also qualified comfortably, winning Heat 5 with a time of 43.729 seconds.
Koreans set pace ahead of 3,000m relay showdown
A number of the skaters were back in action later in the morning for the women’s 3,000m short track relay semi-finals, in which the Republic of Korea confirmed their medal credentials with the fastest time.
The Korean quartet (Ha-Ri Cho, Sang-Jeong Kong, Seung-Ho Park and Suk-Hee Shim) logged a time of 4:08.052, which was too quick for Vancouver 2010 silver medalists Canada (Marie-Eve Drolet, Jessica Hewitt, Valerie Maltais and Marianne St-Gelais), who finished in 4:08.871.
Reigning Olympic champions China (Fan Kexin, Li Jianrou, Liu Qiuhong and Zhou Yang) won a slower second semi-final in 4:09.555, outskating Italy (Arianna Fontana, Lucia Peretti, Martina Valcepina and Elena Viviani), who clocked 4:11.282.
Republic of Korea, China, Canada and Italy will compete for medals in next Tuesday’s “A” final, with Russia, Hungary, Japan and the Netherlands all competing for places in the final standings in the “B” final.