Celta were earlier beaten 1-0 at Eibar, completing a miserable run of eight defeats in 10 league games which has left them one place and two points above the relegation zone.
Cardoso is the second coach sacked by Celta this season after Argentine Antonio Mohamed was relieved of his duties in November.
Portuguese Cardoso got off to an embarrassing start to life at Celta by mistakenly declaring in his first news conference that he was taking over at their fierce local rivals Deportivo La Coruna, although he quickly corrected himself.
His first few games in charge were encouraging as Celta earned two victories from his first four games but their results took a turn for the worse in the new year, their plight worsened by injury to top scorer and Spain international Iago Aspas. (Reporting by Richard Martin; Editing by Ken Ferris)