Novak Djokovic rolls into Olympic semifinals with win over Kei Nishikori

Novak Djokovic is cruising through the Olympic men's singles tournament in Tokyo. (Usa Today Sports)

Novak Djokovic is two wins away from his first Olympic title and is showing no signs of slowing down. 

Serbia's twenty-time Grand Slam champion and four-time Olympian cruised through his quarterfinal match against Japan's Kei Nishikori, taking the win 6-2, 6-0 in 71 minutes. None of his four matches in Tokyo have gone to three sets. 

The victory was Djokovic's 69th straight as he continues his pursuit of a calendar Golden Slam (winning all four Grand Slams plus the Olympics in one year). He'll face either Alexander Zverev or Jeremy Chardy in the semifinals. 

Nishikori, the 2016 Olympic bronze medalist, was the host nation's last hope for a singles tennis medal after No. 2 seed Naomi Osaka was knocked out in the third round on the women's side. 

Japan's Ena Shibahara and Ben McLachlan are still alive in the mixed doubles tournament, playing in the quarterfinals later on Thursday.