Kawasaki Frontale scored a resounding 3-1 victory over Muangthong United in the first leg of the Asian Champions League round of 16 on Tuesday.
After Teerasil Dangda handed the hosts the lead in the third minute of first-half injury time, Kawasaki captain and reigning J-League MVP Kengo Nakamura, Yu Kobayashi and Hiroyuki Abe netted three unanswered goals in the second half.
The Asian Football Confederation charged Kawasaki Frontale with discrimination on Thursday after their fans raised a controversial wartime Japanese flag during a midweek Asian Champions League match in South Korea.
According to article 58.3 of the AFC's disciplinary and ethics code, the team could face a minimum penalty of playing two matches in an empty stadium plus a fine of at least $15,000.
On a night when both teams were sporting throwback uniforms, the SoftBank Hawks introduced a throwback player, former big leaguer Munenori Kawasaki in Friday's 3-1 Pacific League win over the Orix Buffaloes.
A crowd of 22,293 witnessed the return of the Hawks' fan favorite on a night when the Buffaloes sported the red, white and blue of the defunct Kintetsu Buffaloes, while the Fukuoka-based Hawks wore the green of their Osaka-based forbearers, the Nankai Hawks.
Two Kawasaki Frontale supporters nearly caused a post-match riot by angering some Suwon Bluewings fans when they raised a controversial Japanese wartime flag in an Asian Champions League match in South Korea on Tuesday.
After Kawasaki's 1-0 victory to Suwon in Group G, offended Suwon fans faced off with Kawasaki fans in the stands at Suwon World Cup Stadium, with a brawl breaking out as they blocked visitors trying to head for the exit.
Gamba Osaka squandered a two-goal lead, missed a penalty and conceded a last-gasp equalizer as their slim hopes of reaching the knockout phase of the Asian Champions League suffered a major blow with a 3-3 draw at home to Australia's Adelaide United on Tuesday.
But it was not all bad news for Japanese clubs in the continent's elite competition, as Kawasaki scored their first win of the group phase, edging South Korea's Suwon Bluewings 1-0 away to stay in the hunt for a place in the last 16 in Group G.