By Brian Homewood
BUENOS AIRES, Sept 14 (Reuters) - Argentine championship leaders Boca Juniors lost their 100 percent record on Sunday when they were held 1-1 at home by nine-man Independiente in a game of controversial refereeing decisions.
Rodrigo Palacio opened the scoring for Boca 30 seconds after halftime but Dario Gandin, unmarked at the far post, headed in Daniel Montenegro's cross for Independiente four minutes later.
Montenegro was involved in the game's most curious incident in the 75th minute when he upended Gabriel Paletta with a crunching late tackle.
Montenegro was shown a yellow card and went off for treatment but, when he returned to the field, was sent off for coming on to the pitch without permission.
Referee Pablo Lunati, who consulted the fourth official before producing his red card, was surrounded by furious Independiente players.
The visitors also had Guillermo Rodriguez sent off for dissent in the 87th minute and claimed they should have been awarded a goal in the first half when Nunes's shot hit the underside of the crossbar and bounced down.
"The ball crossed the line and bounced out," Independiente coach Claudio Borghi told reporters.
Boca have 10 points from four games and top the Clausura table on goal difference from San Lorenzo, who beat Rosario Central 2-1 on Saturday and have played a game more.
Defending champions River Plate remained stuck in 11th place with six points after being held 2-2 by Arsenal.
River went ahead in the 19th minute when Cristian Villagra cut inside a defender and placed his shot just inside the far post but Carlos Castiglione levelled six minutes before halftime with an almost identical effort.
Midfielder Javier Yacuzzi put Arsenal in front when he scored with a deflected free kick just after the hour and Colombian forward Radamel Falcao Garcia headed River's equaliser nine minutes later.
Arsenal had Cristian Pellerano sent off for a second bookable offence in the 84th minute.
