This isn't a means for me for me to WOW TBC Gold participate in the ongoing debate about "did Thrall cheat using magic?" The war shouldn't have ended in this way. Thrall shouldn't have had to use his elemental abilities.
Garrosh is described as all strength, while Thrall is half-magic and half strength. Thus, as the fight drags on , naturally the stronger and more buy WOW TBC Classic Gold physically strong would gain the upper hand, prompting Thrall to turn to his shaman spells to be victorious.