Gennaro Gattuso has been appointed the new head coach of Napoli, the Serie A club have confirmed.
The former Milan coach and midfielder takes charge at the San Paolo following Tuesday's dismissal of Carlo Ancelotti.
Gattuso twice won the Champions League as a player under Ancelotti in a hugely successful spell with Milan.
Ancelotti's exit was announced just hours after Napoli's 4-0 win over Genk secured their place in the last 16 of the Champions League.
Their success in Europe has belied a mostly troubling few months, marred by poor domestic form and disputes within the club.
Napoli are seventh in Serie A, with just five wins from 15 games leaving them 17 points adrift of leaders Inter.
Disharmony between the players and president Aurelio De Laurentiis appeared to reach a head last month when the first-team squad apparently refused to attend a week-long training camp.
The club suggested in a statement that it could punish players, possibly with fines, promising to do "everything in its power to protect its economic interests, assets, image rights and disciplinary interests".
Tuesday's win over Genk was Napoli's first since a 3-2 victory away to Salzburg on October 23, their nine-game winless run piling greater pressure on Ancelotti.
The 60-year-old former Bayern Munich and Real Madrid boss has been linked with Premier League clubs Arsenal and Everton.
"I would like to personally thank the club, its employees, my players, my staff and the president for the opportunity to live an unforgettable experience in a wonderful city such as Naples," Ancelotti tweeted on Wednesday.
Gattuso, 41, took over as Milan coach following Vincenzo Montella's dismissal in November 2017, but he left his post at the end of last season after failing to secure Champions League qualification.