Rapper J Hus made a surprise appearance when Drake introduced him on stage four months after being jailed for carrying a knife.
The music star was jailed in December for having a knife outside a major London shopping centre.
Canadian rapper Drake brought him out to fans at the O2 in London on Friday night.
“Anybody sitting down right now, I need you to stand up, because (we’re) about to celebrate one of our brothers tonight,” Drake said.
Surprising fans who did not know he had been released from prison, J Hus walked out on stage, which featured the words Welcome Home, and told the crowd: “I’ve missed you so much.”
Drake told J Hus: “I’ve been waiting for this all week. I wanna give you this stage so you can do exactly what you’ve been waiting to do.”
J Hus – real name Momodou Jallow – had apologised in court and said he regretted his “foolish actions” – carrying the 4in (10cm) blade near Westfield, in Stratford, east London, in June.
In a letter read to the court by his barrister, the rapper said: “My decision to carry a weapon was careless, ill-advised and utterly stupid.
“Being a public figure that many look up to, I simply should have known better.”
The rapper won best song at the Mobo awards in 2017.
He had been sitting in his Audi with a female at the wheel and another passenger outside Westfield when they were stopped by police.
Prosecutor Helen Owen said there was a smell of cannabis from the vehicle and, when asked by an officer if he had anything on him, the star said he had a knife in his pocket.
Asked during the incident why he was carrying what was described in court as a folding knife, he replied: “You know, it’s Westfield.”
The court heard that J Hus’s friend had been knifed and paralysed just days earlier and that the rapper, who was himself stabbed in 2015, feared he would be the victim of another attack.