China outnumbered Japan for the first time in the annual Times Higher Education Asia University Rankings released Wednesday.

Although the University of Tokyo was once again judged to be the best university in the region encompassing Asia and the Middle East, China has 21 institutions in this year’s top 100, up from 18 last year, while Japan has 19, down from 20 last year and 22 in 2013.

To make matters worse for Japan, 15 of the 19 Japanese institutions in the top 100 have lost ground in the rankings.

South Korea took third spot with 13 universities and Taiwan fourth with 11 institutions.

By university, the National University of Singapore again ranked second and the University of Hong Kong was ranked third.

Japan’s second-best institution, Kyoto University, came ninth, and Tokyo Institute of Technology 15th, both down two notches from last year.

China’s top-ranked institutions gained ground, with Peking University taking fourth place and Tsinghua University fifth. Also, six universities from Hong Kong and one from Macau were in the top 100.

“Although Japan once led Asia’s progress towards superpower status, it must now up its game and invest more in research to compete with its main rival, China,” said Phil Baty, editor of Times Higher Education Rankings.

“Now is not the time for it to rest on its existing reputation. It must act, and quickly, if it is to arrest its decline,” he added.

The rankings are based on 13 indicators to determine how each university performs in all its core missions: teaching, research, knowledge transfer and international outlook.