BUENOS AIRES, May 1 (Reuters) - Boca Juniors, thriving without the distraction of the Libertadores Cup, closed in on the Argentine title with an emphatic 4-0 win over Estudiantes on Sunday.
Boca, who have 37 points from 17 games, are four points clear of Lanus with two matches each to play in the Clausura championship and six ahead of River, who dropped to third after drawing 3-3 with Gimnasia-La Plata.
Boca got a helping hand as both Estudiantes and River rested their top players ahead of Libertadores Cup ties next week.
Midfielder Federico Insua broke the deadlock for Boca in the 20th minute when he left two defenders in his wake before scoring with a left-foot shot.
Insua also added the third in the second half with Rodrigo Palacio and veteran Guillermo Barros Schelotto helping themselves to the other goals.
'At times, we played brilliantly,' said coach Alfio Basile. 'It was the sort of football people like to see.'
River were denied a win when Uruguayan striker Gonzalo Vargas scored an injury-time equaliser for Gimnasia.
Gimnasia had gone ahead when Martin Cardetti scored against his own club in the 16th minute before Gonzalo Higuain and a Rubens Sambueza penalty put River 2-1 ahead.
Roberto Cornejo levelled in the 57th minute and Jeronimo Morales put River back in front with nine minutes left.
Lanus moved into second place after scoring three times in the first half hour to beat Arsenal 3-0.
Sebastian Leto, midfielder Agustin Pelletieri and Santiago Biglieiri shared the goals while Lanus had defender Leandro Gioda sent off for a bad challenge in the 89th minute.
Racing Club, coached by former Argentina captain Diego Simeone, won their third straight game as they beat Tiro Federal 2-0.