Argentina derby delayed by crowd trouble
The start of the match was delayed for around 30 minutes after police sprayed tear gas on sections of the crowd after they began fighting on the terraces.
Players and officials were forced to retreat to the changing rooms as the gas wafted on to the pitch and around 20 people were injured and two arrested, local media reported.
The fighting broke out when Huracan fans unfurled a banner with the colours of their rivals, a practice regarded as provocative and banned by local authorities.
When the match eventually began, San Lorenzo triumphed 2-0, ending a run of two successive defeats after former Olympique Marseille defender Renato Civelli opened the scoring with an early goal.
Uruguayan striker Santiago "Tank" Silva scored the winner as Banfield came from a goal down to beat Independiente 2-1 while Atletico Tucuman beat Chacarita Juniors 2-1 in Saturday's other matches in the Apertura championship.
Banfield have 35 points from 15 matches, Newell's have 32 and third-placed Estudiantes have 29 but have played an extra match.
South American champions Estudiantes beat bottom team Tigre 3-1 on Friday night.