BUENOS AIRES, Sept 17 (Reuters) - Argentine champions Boca Juniors were held to a goalless draw at home by lowly Godoz Cruz on Sunday, ending a run of 12 successive league wins in their first game under new coach Ricardo La Volpe.
La Volpe, a former goalkeeper who coached Mexico at the World Cup, replaced Alfio Basile, who has been named as the new coach of Argentina.
River Plate and San Lorenzo both won to pull level on 16 points with Boca, who lead on goal difference and have one game in hand.
The weekend was marred by more crowd trouble after Saturday's Colon-Velez Sarsfield game was called off in the first half when a linesman was struck by an object thrown from the crowd.
Colon were winning 1-0. It was the third game which has failed to finish since the season began last month.
Boca, who last failed to win a domestic game on March 29 when they drew 1-1 at Newell's Old Boys, were on the brink of equalling the record of 13 straight wins set by San Lorenzo in 2001.
But they struggled against a well organised visiting defence and were repeatedly foiled by goalkeeper Sebastian Torrico.
'The opposition was very well positioned,' La Volpe said.
'I imagine they set out with the intention of 0-0 and they achieved it. We tried to open them up in a number of ways but the team was tired.'
River won 2-1 at Gimnasia-Jujuy in a game preceded by clashes outside the stadium in which the visiting team's bus was stoned.
A spectacular injury-time goal from midfielder Nicolas Domingo gave River the points as they came from behind.
Dario Gandin had put Gimnasia ahead after seven minutes direct from a free kick, Fernando Belluschi equalising before halftime as he chested home Gonzalo Higuain's cross.
A second-half strike from Andres Silvera gave San Lorenzo the points against Independiente in a match which pitted two former team mates from the 1986 World Cup against each other on the touchline.
Independiente are coached by Jorge Burruchaga, who scored the winning goal in the final against West Germany, while San Lorenzo are led by Oscar Ruggeri, an uncompromising defender in the same side.
Former Costa Rica striker Paulo Wanchope headed the only goal as Rosario Central beat Estudiantes, who were missing former Argentina midfielder Juan Sebastian Veron with a back injury.
It was Wanchope's third goal of the competition.
Estudiantes, coached by former Argentina captain Diego Simeone, have failed to win in their last four games.