Novak Djokovic remains on course for a 'Golden Slam' after ruthlessly ending the dreams of home hope Kei Nishikori to cruise into the Olympic semi-finals.

He will face Germany's Alexander Zverev or France's Jeremy Chardy in the semis.

Earlier, Switzerland's Belinda Bencic beat Elena Rybakina 7-6 (7-2) 4-6 6-3 to reach the women's singles final.

The Swiss will meet the winner of Thursday's remaining semi-final between Ukraine's Elina Svitolina and Marketa Vondrousova of the Czech Republic.

Bencic, 24, outlasted Kazakhstan's Rybakina in a match lasting almost three hours in the searing Tokyo heat, saving five set points in a 73-minute opening set that she won on a tie-break.

Thursday's matches began at 15:00 local time (07:00 BST), four hours later than on previous days, after organisers agreed to push start times back following complaints from players about the hot conditions.

There were few concerns about the heat for Djokovic as he took just an hour and 10 minutes to dispatch Japan's 2016 bronze medallist Nishikori, who cut an increasingly forlorn figure as his hopes of winning a medal for the host nation were obliterated.

Victory equalled another record for the Serb, who drew level with Roger Federer and Rafael Nadal on 20 Grand Slam titles at Wimbledon last month, as he matched the Swiss' 13 singles match Olympic wins.

Djokovic, however, has never reached an Olympic final, his best performance coming in Beijing in 2008 when he took bronze after losing to Nadal in the last four.

Spain's Pablo Carreno Busta will meet Karen Khachanov, of the Russian Olympic Committee, in Friday's other semi-final at the Ariake Tennis Park.

The Spaniard upset world number two Daniil Medvedev, who struggled in the intense heat in his previous match, 6-2 7-6 (7-5), while Khachanov triumphed 7-6 (7-4) 4-6 6-3 over France's Ugo Humbert.