Silvio Trucco didn’t have his best night of officiating in Formosa on Monday night but after disallowing three Boca goals, Cristian Pavón eventually struck an offside winner for Guillermo Barros Schelotto’s side against Santamarina.
Darío Benedetto headed Boca into an 18th minute lead but having failed to add a second and kill the tie off, Martín Michel snatched an equaliser midway through the second half with a powerful drive from over 30 yards out.
With the prospect of penalties nervously approaching Boca sealed the win when Benedetto stabbed the ball through to Pavón, in an offside position, and he steered the ball into the bottom corner.
Barros Schelotto was not pleased with his side’s performance but the champions took their place in the last 16 where a difficult tie against Lanús awaits.
Boca Juniors 2 – 1 Santamarina