Porto, Portugal (SportsNetwork.com) - Reigning Portuguese champions FC Porto have sacked head coach Paulo Fonseca on Wednesday after just nine months in charge.

Fonseca, 41, was shown the door after his team sustained a four-match winless streak which saw them drop nine points behind current leaders Benfica.

Porto's five-and-a-half-year unbeaten home record was ended by Estoril last week before they surrendered a 2-0 lead to draw at Guimaraes on Sunday.

Reserve team coach Luis Castro has been named as interim manager.

Porto are the 27-time Portuguese champions, having won the title in each of the past three seasons. They were knocked out in the Champions League group stage this season, but have reached the last 16 of the Europa League, where they face Napoli.

Fonseca succeeded Victor Pereira in June 2013 after taking Pacos de Ferreira into the Champions League for the first time in their history.

He was the club's eighth coach in 10 seasons since the departure of current Chelsea boss Jose Mourinho, who led the side to the 2003 UEFA Cup and 2004 Champions League title.