The incident happened outside the CF Eaton Center on Yonge and Dundas streets before 7:30 p.m.
Police said two men got into a verbal altercation when one of them stabbed the other.
The victim was taken to hospital with life-threatening injuries. On Wednesday, police said they were in stable condition.
The suspect, a Toronto resident, Akwasi Oppong-Nsafoah, was subsequently arrested after the incident and charged with two counts of assault with a weapon and one count of aggravated assault.
He appeared in court Wednesday morning.
Police continue to ask anyone with information about the knife, including those driving in the area at the time, to call investigators at 416-808-5200 or Crime Stoppers anonymously at 416-222-TIPS (8477). ).