Olympics 2021: 3 talking points from Novak Djokovic's shock semifinal loss to Alexander Zverev 

Novak Djokovic's hopes for a Calendar Golden Slam were crushed by German fourth seed Alexander Zverev, who pulled off a stunning upset in the semifinals of the men's singles event at the Tokyo Olympics on Friday.

Zverev trailed by a set and a break but fought back magnificently to hand the Serb a crushing 1-6, 6-3, 6-1 defeat.

Down a break at 2-3 in the second set, Zverev switched gears, winning eight consecutive games, including four successive breaks of the Serb's serve. The German hit 30 winners in total, with 23 of those coming in the last two sets.

Zverev will take on ROC's Karen Khachanov in the gold medal match while Djokovic will hope to get his hands on the bronze when he faces Spain's Pablo Carreno Busta.

On that note, here are 3 talking points from Djokovic's loss to Zverev:

#1 Did Calendar Golden Slam pressure finally get to Djokovic?

Djokovic's level uncharacteristically dropped midway through the second set. Although the German played extremely well, Djokovic looked flustered, with the pressure of the Calendar Golden Slam potentially getting to him.

Djokovic struggled to land his first serve consistently and also committed 16 unforced errors. Moreover, he won a meager 10 out of 26 points on his second serve, which contributed to his downfall.

#2 Zverev appears to have solved his second serve issues

Alecander Zverev

A major talking point of late has been Zverev's inconsistent second serve and how it crumbles under pressure.

Just a couple of months ago, he served 14 double faults in his loss to Ilya Ivashka in Munich. He also hit 20 double faults against Felix Auger-Aliassime as he crashed to a fourth-round loss at Wimbledon.

However, he seems to have fixed that aspect of his game. The German has committed just three double faults in the singles event at the Olympics so far, one of which came against Djokovic in the semifinals.

#3 Not all is lost for Novak Djokovic

Djokovic will still have a chance to win a bronze medal when he takes on Spain's Pablo Carreno Busta on Saturday.

The Serb could also earn a shot at the gold medal in the mixed doubles event alongside Nina Stojanovic if they win their semi-final encounter against Russia's Aslan Karatsev and Elina Vesnina later today.

Djokovic will also have a chance to become the first player since Rod Laver to win all four Slams in a year when he takes part in the US Open, which begins next month.