A cross in from the right fell to Ariel Nahuelpan at the back post, and his left-footed half-volley looked like it was destined to hit the back of the net, but the Brazilian goalkeeper launched himself at the ball with his arms outstretched and somehow managed to keep the strike out from point-blank range.
Not only did Grohe, who has been capped twice for Brazil, get a strong hand to the ball, he also reacted quickest to pounce on the loose ball to deny any rebound.
Gremio had a 2-0 lead when Grohe made the sensational stop, and the Brazilian side went on to score another goal to give them a three-goal advantage in the first leg, so the stop could be vital as the teams prepare for the return leg in the next few days.
Should Gremio advance to the final, they will become the first Brazilian side to do so since 2013 and they will face one of the Argentinian pair Lanus or River Plate.
Check the brilliant save out for yourself below:
Marcelo Grohe. Barbaridade. pic.twitter.com/ztuPP8KK16
— Sem Firulas (@sem_firulas) October 26, 2017