Novak Djokovic’s dream of a Golden Slam is over.

Alexander Zverev of Germany stormed back from a set and a service break down to beat Djokovic, the world’s No. 1 ranked men’s player, 1-6, 6-3, 6-1.

Djokovic was attempting to win all four Grand Slam tournaments and the Olympic gold medal in a calendar year. He had won the Australian Open, the French Open and Wimbledon and came to Tokyo looking for the fourth jewel. The United States Open takes place at the end of the summer.

Djokovic appeared to be on cruise control when be broke Zverev’s serve to get to within three games of the match in the second set. Zverev swatted a ball through the stadium roof in frustration and looked destined to meet with a quick end like Djokovic’s first four victims in Tokyo. He had not lost a set at the Olympics and said he was getting better with each match.

But with little to lose, Zverev began unleashing his booming serve and setting up a crushing forehand to take control of the match, just as Djokovic started inexplicably spraying his shots off the court. Djokovic tried to slow Zverev’s momentum with a long bathroom break between the second and third set, as he has done in tense moments in the past, but it didn’t work, and in the two-of-three set format he did not have the cushion afforded by the three-of-five set Grand Slam matches give him.

After Zverev reeled off seven consecutive games with seeming ease, sprinting to 4-0 lead in the deciding set, Djokovic faced a mountain too difficult even for a player who had already staged several stunning comebacks in the first three Grand Slams this year.

As a final insult, Zverev broke Djokovic’s serve for a third time in the last set to take the match. He grabbed his face in disbelief and embraced the Serbian champion at the net when it was over, then stared at the sky wondering what had just happened.