Lewis Barker, aged 27, pleaded guilty at Sheffield Crown Court this morning to the murder of Jarvin Blake.
Mr Blake, aged 22, who had three children under five, was stabbed to death at the junction of Catherine Street and Brackley Street in Burngreave on March, 8, 2018.
Barker, of Parson Cross, who was wearing a sweater and jogger bottoms, was due to stand trial alongside three other men.
Remanding him in custody, Judge Jeremy Richardson QC said: “You have pleaded guilty to the charge of murder. You will fall for sentence.
“There is, of course, a life sentence that must be imposed upon you. The minimum term is what is crucial at this time.”
Josiah Foster, 26, of the Manor, Sheffield; Devon Walker, 24, of Burngrave, Sheffield and Caine Gray, 27, of Treeton, Rotherham, are also all charged with the murder of Mr Blake.
They are due to stand trial this week and it is expected to last around a month.
Judge Richardson told Barker he would be sentenced following the trial.
Hundreds of mourners attended Mr Blake's funeral last April, where he was described as having a 'heart of gold'.
Rev David Bussue said: "The truth is words are never enough and the tragic and pointless nature of Jarvin's death means that words sound even emptier and even more hollow.
"Some things in life just don't make sense. We shouldn't be here today, Jarvin should be here today. He should be here to support Kelsey with his three lovely children.
"When I spoke to the family and asked them to just tell me things about Jarvin, one of the first things they said to me was the best way to sum Jarvin up was that he had a heart of gold.”
A 23-year-old man also injured during the attack has since made a full recovery.