Thrall isn't quite sure what WOW TBC Gold he's fighting. He's not fighting Garrosh to bring Garrosh know what he did wrong or to make him kill him. Instead, he is fighting Garrosh because he feels guilty. Garrosh On the other on the other hand, knows precisely the reason he's fighting- to punish Thrall. Garrosh kicks Thrall until Thrall realizes that there is no way to save him and that Garrosh must be taken to court.
Garrosh has plenty of experience fighting powerful adversaries. Without Gorehowl, he nearly defeated Thrall during their first Mak'gora. After cutting cheap WOW Classic TBC Gold Thrall off from the elements He easily beat Thrall during their second fight. It's natural that he'd win their third fight before elements began to take over.