Him and his father and brothers own a gym in Nichelino (Turin, Italy) with the purpose of giving an alternative chance to the young guys living poor in the area he's also grown up into.
Grandelli made his professional debut on 23 May 2015, scoring a four-round points decision (PTS) victory over Marco Iuculano at Pala Hilton Pharma in Ferrara, Italy.
In July, Grandelli defeated Tiganas in a rematch via third-round technical knockout (TKO)[8] followed by a PTS win over Shoaib Zaman twenty days later.
[10] After only fighting once in 2017—a TKO victory over Stefan Slavchev in July[11]—Grandelli defeated Emiliano Salvini via unanimous decision (UD) over ten rounds to capture the vacant Italian featherweight title, with the judges scoring the bout 99–91, 99–92 and 98–93.
[13] Following a PTS win over Wallington Orobio in April 2019,[14] Grandelli defeated Nicola Cipolletta by UD over ten rounds to capture the vacant Italian featherweight title for a second time.