The Cleveland Cavaliers entered their Eastern Conference finals series matchup with the Boston Celtics with a surplus of confidence after sweeping the conference’s No. 1 seed Toronto Raptors in the second round. Also, prior to Game 1 of the conference finals, Cavs owner Dan Gilbert posted a message to Cleveland fans on his Twitter account in which he gave praises for general manager Koby Altman, head coach Tyronn Lue, and stars LeBron James and Kevin Love.

All that confidence, however, went down in flames Sunday after Boston eked out a comprehensive 108-83 victory. It was a painful punch to Cleveland’s gut, as the team was labeled as the favorite to win the series despite not having the home-court advantage.

Dan Gilbert, however, has seen his Cavs team come out of a deeper hole than a 0-1 series deficit before. It was not a long time ago when James and company overcame the Golden State Warriors’ 3-1 lead in the 2016 NBA Finals. More recently, the Cavs won their first-round matchup with the Indiana Pacers even though they lost Game 1 of that series.

Gilbert will be cheering for his Cavs again this Tuesday when Cleveland and Boston play Game 2 of the series at TD Garden. The Cavs are 4-1 in their last five games following a loss.