CONMEBOL confirmed the referee trio for the first‑leg semifinal between Boca Juniors and Vasco da Gama on Tuesday, 13 October, kick‑off 21:30 at La Bombonera, where the Xeneizes will look to seize an edge before the return in Brazil.
The match will be led by Chilean Piero Maza, assisted by fellow countrymen José Retamal and Carlos Poblete, with Mathías Riquelme serving as fourth official for the clash that opens the race for a continental final spot.
Maza’s selection marks his third straight first‑leg Boca assignment in this Sudamericana edition, following his stewardship of ties against Deportivo Recoleta and São Paulo during the Argentine side’s campaign.
At La Bombonera, Maza oversaw Boca’s 1‑0 victory over São Paulo and earlier the win over Deportivo Recoleta, returning now to direct a Rodolfo Arruabarrena‑led side in a pivotal stage.
How the officiating crew is composed
The VAR crew is also Chilean: José Cabero will run the video‑referee system, with Juan Serrano as his assistant. For my money, appointing an all‑Chilean team underscores CONMEBOL’s confidence in their consistency.
Maza’s Boca résumé includes a 1‑0 triumph over Deportivo Cali in 2022 and a goalless draw with Nacional Potosí in Bolivia during the 2024 Copa Libertadores.
He also officiated a 2025 Copa Libertadores encounter where Boca beat Alianza Lima 2‑1 before exiting on penalties.
Maza’s previous involvement with Vasco da Gama. Will Maza’s familiarity with both sides tilt the balance in Buenos Aires?
For Vasco da Gama, Maza recently handled a 2‑2 draw with Independiente Medellín in this season’s Sudamericana playoffs.
The tie kicks off in Buenos Aires and concludes in Brazil, with the return set for Rio’s Nilton Santos Stadium after the Fla‑Flu consortium declined to lend the Maracanã.
v
With the referee slate set, Boca and Vasco da Gama gear up for a series that opens at La Bombonera and decides one of the Sudamericana finalists.