Napoli fires Garcia after 3rd loss of Serie A campaign and rehires Mazzarri.
Napoli have sacked head coach Rudi Garcia after 16 games and have replaced him with former manager Walter Mazzarri until the end of the season.
Frenchman Garcia, 59, was appointed by the Serie A champions in June, but departs with the club 10 points behind league leaders Inter Milan.
Mazzarri spent one season in the Premier League at Watford in 2016-17 before his contract was terminated.
The 62-year-old Italian previously managed Napoli from 2009 to 2013.
Mazzarri delivered the club its first trophy in 20 years when Napoli won the 2012 Copa Italia by beating undefeated league champions Juventus in the final.
A year later, he led them to second in Serie A - the club's highest league position in over two decades - and secured a Champions League place.
Garcia was named Napoli boss in the summer after Luciano Spalletti left the club to take time out of the game last season after delivering the club their first league title for 33 years.
Napoli are currently fourth in table and were beaten by 17th-placed Empoli on Sunday to leave Garcia with a record of eight wins, four draws and four defeats.