Juan Roman Riquelme starred for Boca Juniors as they defeated city rival Racing Club 2-1 in a tight clash at the Bombonera stadium on Sunday.
Boca went ahead in the 40th minute, when Riquelme beat Pablo Migliore with a well-placed penalty kick. But Racing replied just before the break, when Franco Sosa found the back of the net with a powerful header.
In the 59th minute Riquelme scored what ended up being the eventual match-winner with a superb volley.
It was a valuable victory for Boca, which remains in contention for its first championship since 2006, and its first under Carlos Ischia.
Tigre remains in the title hunt, two points behind Boca Juniors, after coming from behind to defeat Argentine champions River Plate 3-1 in Victoria.
Santiago Salcedo put River ahead within two minutes of the kickoff, with a brilliant curling free-kick, but Carlos Luna scored twice (26', 41') to give Tigre an advantage going into the halftime break.
In second-half injury time, Cristian Bardaro sealed Tigre the win, with a deft chip over Daniel Vega after meeting a good through ball from Martin Morel.
In Sunday's other matches, Newell's Old Boys edged Velez Sarsfield 1-0 and Argentinos Juniors and Rosario Central fought out a scoreless draw.
The clash between fierce rivals Huracan and San Lorenzo, which was staged at La Bombonera due to security concerns, was suspended in the first half because of torrential rainfall.
Huracan was winning the match 1-0 courtesy of a goal from Paolo Goltz. The rest of the encounter will be played on Tuesday. Lanus defeated Arsenal de Sarandi 2-1, and Gimnasia y Esgrima de Jujuy edged out San Martin de Tucuman 1-0.
In the match that inaugurated the round on Friday, Banfield waited until second-half injury time to snatch the three points against Independiente. Its goal was scored by Victor Ruben Lopez.
Finally, Gimnasia y Esgrima de La Plata edged Colon de Santa Fe 1-0, with a strike from Denis Stracqualursi 10 minutes from full time.