He only lost his final battle against Thrall. It's true that he lost his second fight against Varian as well as his duel against Cairne. He was defeated the WOW TBC Gold first time and was eventually cut short, and he also won the second fight unfairly.
They had three fights, and each time were stopped. Varian takes the victory in Wolfheart due to his unlimitable endurance and is blessed with Lo'Gash. They're equally matched as they fight in tides of War.
He was a Mary Sue from the beginning. He was cheap Burning Crusade Classic Gold a much better warrior than Orgrim Doomhammer. He was also an adept in the art of shamanism.