According to the Green500 rankings, Gyoukou isn't the most efficient computer in the world - in that it's beaten by three other Japanese systems built with the Pezy-SC2 accelerators and a USA one built with Nvidia Tesla V100s - but it's by far the fastest system to prove so efficient.
The new TOP500 list also has China overtaking the U.S. in the total number of ranked systems by a margin of 202 to 144.
"It is the largest number of supercomputers China has ever claimed on the TOP500 ranking, with the US presence shrinking to its lowest level since the list's inception 25 years ago", Top500 said.
What's interesting, the report noted, is that these rankings weren't the case a mere six months ago.
When it comes to companies making these systems, the US -based Hewlett-Packard Enterprise has the lead in the number of installed supercomputers at 123, which represents almost a quarter of all TOP500 systems.
The rise of Gyoukou in the Top500 bumped the US systems Titan (built by Cray) and Sequoia (IBM) down a place, while seventh place was snatched by another Cray system, Trinity, which has recently been upgraded from 8.10 petaflops to 14.14 petaflops.
Experts also predicted that Summit, a system now being developed by the U.S. Department of Energy, could dethrone China's TaihuLight next year, when it comes to run with an expected performance of 200 petaflops.
China has also overtaken the United States in aggregate performance as well. The US had 29.6%. Now though, the ruler has changed and China is now in possession of most of the world's fastest supercomputers. The TaihuLight can hit 93.01 petaflops.
Another Chinese supercomputer called Tianhe-2, or Milky Way-2, has once again occupied the number two position with 33.86 petaflops. Japan clocks in at third and Germany at fourth with 35 and 20 supercomputers respectively.
The fourth position was claimed by Japan's Gyoukou, which pushed Titan - the top USA system - to the fifth spot. Tianhe-2, which is based on Intel chips, was the number one system on the TOP500 list for three consecutive years until Sunway TaihuLight displaced it in June last year.
Despite the role reversal of China and the USA in the recent TOP500 ranking, the two countries continue to dominate the list with little to no close competitors.
The standing corresponds with China's growing reputation as the global leader in supercomputers, as the Asian power prepares to launch in June 2018 a prototype exascale computing machine - a "super supercomputer".