Novak Djokovic cruised through to the men's singles semi-finals after a commanding straight-sets victory over Kei Nishikori at the Ariake Tennis Park.
The world number one is yet to drop a set at the Tokyo Games after running out a 6-2 6-0 winner against home favourite Nishikori, who claimed bronze in Rio five years ago.
Having already won the Australian Open, French Open and Wimbledon this year, Djokovic is aiming to become the first male player of the Open era to complete the Golden Grand Slam.
Should he claim gold in Tokyo and go on to triumph at the US Open, he would become only the second player overall to achieve the feat, after Steffi Graf in 1988.
However, the Serbian has never reached an Olympic final – his best result coming in for the form of a bronze medal in Beijing.
"Matches are not getting easier, but my level of tennis is getting better and better," Djokovic told reporters after setting up a last-four tie with Alexander Zverev.
"I've done that many, many times in my career. I know that I'm the kind of player that the further the tournament goes, the better I'm feeling on the court.
"That's the case here, [it was] my best performance of the tournament tonight against a very good opponent."
DANIIL DUMPED OUT
Standing in the way of Djokovic and a shot at the gold medal is fourth seed Zverev.
The big-serving German saw off Jeremy Chardy 6-4 6-1 and like Djokovic is yet to drop a set at the tournament.
World number five Zverev, who hit 11 aces during the contest, broke early on the way to edging a closely fought opening set. The US Open finalist then went into overdrive with three breaks on the way to sealing the deal.
There was, however, no joy for second seed Daniil Medvedev, as he went down 2-6 6-7 (5-7) against Spain's Pablo Carreno Busta, who is looking to replicated Rafael Nadal's effort from 2008.
"Today, he could win a Masters easily, and yet he's never been in any final of those," the Russian said of his opponent.
"With the level he showed here today, he can get to the final of a Grand Slam easily. I couldn't play better than what I did today. It was not easy to play and I'm really disappointed with myself and for my country to lose in the quarters."
FROM RUSSIA WITH LOVE
Despite Medvedev's exit, Russia – or, at least, the Russian Olympic Committee – will be represented in the semi-finals by Karen Khachanov.
A quarter-finalist at Wimbledon earlier this month, the 12th seed built on his momentum by overcoming Ugo Humbert in three sets.
Khachanov took the opener on a tie-break but was pegged back by the Frenchman in the second as the contest went to a decider.
But he established early control by breaking to love in game four before holding out to prevail 7-6 (7-4) 4-6 6-3.