BUENOS AIRES, Dec 13 (Reuters) - Boca Juniors coach Ricardo La Volpe said he would resign after they lost 2-1 to Estudiantes in a playoff for the Argentine championship on Wednesday.
'I have to present my resignation because we didn't achieve our target,' La Volpe told Argentine television as soon as the match finished.
La Volpe, who coached Mexico at this year's World Cup, took over in September, inheriting a team that had won the previous two titles under Alfio Basile.
But his side missed out on a third successive title in dramatic circumstances.
Leading the table by four points with two games to go, they lost to modest Belgrano and Lanus and allowed Estudiantes to pull level on 44 points from 19 games.
This sent the title race to Wednesday's playoff, where Boca lost despite taking a fourth-minute lead.
As he left the stadium, the gruff La Volpe told reporters: 'The coach always has to win and when that doesn't happen, he has to go.'
Boca Juniors president Mauricio Macri, who had previously backed the coach, said he had not been officially informed of La Volpe's decision.
'I still haven't spoken to Ricardo, nor have I seen him,' said Macri.
'We didn't win the title but we congratulate Estudiantes because they have done a great job.'
La Volpe, reserve goalkeeper in Argentina's 1978 World Cup winning squad, returned to the country to coach Boca after living and working in Mexico for 26 years.
He coached several Mexican clubs and was in charge of the national side from 2002 until the 2006 World Cup, when Mexico lost in the second round to Argentina.
La Volpe gave Mexico a younger and more competitive edge, but he frequently clashed with the media.
Before the World Cup, he was criticised for leaving out playmaker Cuauhtemoc Blanco, for fielding two foreign-born players and including his son-in-law Rafael Garcia in the squad for Germany.
He made a bad start at Boca when they were held to a goalless draw at home by modest Godoy Cruz on his debut, ending a run of 12 successive league wins.
Although Boca continued to lead the competition, there were reports that the players disliked La Volpe's marathon training sessions and did not understand his tactics.
Boca went down 3-1 to arch-rivals River Plate and, after recovering from that blow to lead the table, lost a championship which appeared to be theirs for the taking.