Gremio are unbeaten in their last four official games, with three wins and one draw. Corinthians have suffered only one loss in their last six competitive matches. Three of the previous four direct games have ended without a winner in regulation time.
The Grêmio team plays at home and has the same 15 points as the Corinthians team and in the last four clashes between these teams the draw happened 3 times, so I believe that the best option to bet on this game is the draw.
Home win either half