Nadal, 32, won 6-4 6-3 6-2 to earn his 17th Grand Slam, three adrift of Roger Federer’s all-time men’s record.
The victory means the past six Grand Slam titles have been won by either Nadal or Federer with the next generation of players finding it hard to break the veterans’ stranglehold on the game.
Nadal is the only second player in history to win the same Grand Slam on 11 occasions after Margaret Court, who won 11 Australian Open titles between 1960 and 1973.
Thiem, playing in his first Grand Slam final, simply had few answers to Nadal’s brilliance. Thiem has three career defeats over Nadal all on clay.