Tigre climbed to the top of the Argentinian Clausura standings on Sunday night thanks to a 2-0 win at Banfield, while bottom club Independiente picked up their first win of the season with an amazing 5-4 victory at Boca Juniors.
Two goals in the final six minutes proved the difference for Tigre, substitute Ezequiel Maggiolo breaking the deadlock before Carlos Luna made the points safe in stoppage time.
The result put Tigre three points ahead of third-placed Boca, who overcame an early two-goal deficit to lead 4-3 only for Ernesto Farias to swing the match back in Independiente's favour by completing his hat-trick with two last-gaps goals.
Independiente headed into their match with Boca Juniors having lost all four of the previous games in the competition so far, but were two up within seven minutes through Patricio Vidal and Osmar Ferreyra.
Facundo Roncaglia halved the deficit for Boca after 13 minutes, but Farias' first goal of the night 20 minutes later re-established the visitors' two-goal cushion.
Joan Riquelme got Boca back in the game once more on the stroke of half-time, and the hosts looked to have the points in the bag when further goals from Roncaglia and Pablo Ledesma put them ahead for the first time with 15 minutes left.
However, Farias equalised in the 90th minute and then grabbed a dramatic winner deep in stoppage time to condemn Boca to a first defeat of the campaign.
Goals either side of the interval from Diego Jara and Pablo Daniel Magnin gave Union Santa Fe a 2-0 triumph at Atletico Rafaela, and Jorge Ortiz's seventh-minute strike earned Arsenal Sarandi a 1-0 win at Godoy Cruz.