Penarol coach Mario Saralegui has quit after his team lost 2-1 to Nacional in a friendly, the Uruguayan club said on Sunday.
"The coach presented his resignation last night, after the derby," the five-times former South American champions said on their website (www.capenarol.com.uy). "The club directors accepted his resignation there and then."
Saralegui took over last March and won 11 of his first 14 games in charge as his side reached the final of the 2007/08 Uruguayan championship, where they were beaten by Defensor Sporting.
However, Penarol performed modestly in the first half of the current season.
Penarol were once one of the most powerful clubs in South America, winning a record 36 Uruguayan titles, but have struggled in the last few years and last claimed the league in 2003.