The victim died on the Rue de Carouge after being stabbed several times with an Opinel pocket knife on Saturday night, the Geneva prosecutor’s office said on Tuesday.
He collapsed in front of a bar in the Plainpalais neighbourhood at around 11.30pm, the office said, confirming previous media reports.
The alleged attacker, a naturalized Swiss citizen originally from The Gambia, was arrested by cantonal police at his home on Sunday night.
The victim “was suffering from many cuts from a knife, of the Opinel type, including one fatally to the heart,” Vincent Derouand, a spokesman for the prosecutor’s office told 20 Minutes.
“He died upon his arrival at the hospital.”
The knife was habitually carried by the attacker and was seized by police upon his arrest, 20 Minutes reported online.
The newspaper earlier reported that the attack was brought on after the Senegalese man visited the home of the alleged attacker’s former wife.
The victim, who was known to the woman, was hanging about outside her apartment building when she reluctantly invited him in.
The woman told 20 Minutes that she asked the man to leave because he was drunk but he refused and sat down on a couch.
An altercation ensued, which resulted in the woman losing a tooth when she bit him, the newspaper reported, citing the woman’s evidence.
She fled the apartment and contacted her former husband who confronted the man.
The Senegalese man left, holding his stomach.
The woman said that her ex-husband told her, “I cut him with my knife” but she added “we did not know that was dead”, 20 Minutes reported.
The alleged attacker is in detention at Geneva's Champ-Dollon prison while an investigation into the case continues.