If tied on aggregate, the away goals rule would not be used, extra time would not be played and the penalty shoot-out would be used to determine the winner.
[2] Host teams were settled in a draw held on 21 February 2018, 11:00 at CBF headquarters in Rio de Janeiro.
Tied 0–0 on aggregate, Ponte Preta won on penalties and advanced to the fourth round.
São Paulo won 5–0 on aggregate and advanced to the fourth round.
Tied 2–2 on aggregate, Atlético Mineiro won on penalties and advanced to the fourth round.