Yusuke Mori set up Juninho to put Frontale ahead in the 18th minute, and the home side was boosted by the 26th-minute dismissal of Hiroshima defender Ryota Moriwaki.

Chong Tese, Yusuke Tasaka, Renatinho, Kengo Nakamura, and substitute Kyohei Noborizato scored in the second half, before Juninho completed the rout in the last minute with his 16th goal of the season.

With four rounds left, Kawasaki has 55 points, one ahead of defending champion Kashima Antlers.

Kashima snapped a six-match winless streak on Saturday with a 3-0 win over relegation-threatened JEF United Chiba.

First-half goals from Shinzo Koroki and Marquinhos put Kashima in control before substitute Yuzo Tashiro added a third 12 minutes from time.

Third-place Gamba Osaka is four points off the pace after being held to a 0-0 draw by Yokohama F Marinos.

Shimizu S-Pulse has 50 points and saw its title hopes take a setback after a 2-1 loss to FC Tokyo, which is fifth place on 49 points.

At the other end of the standings, Oita Trinita was relegated after a 1-1 draw with Kyoto Sanga on Saturday. Chiba has 24 points and looks almost certain to join Oita in J2 next season as it is 12 points behind fourth-from-last Omiya Ardija.

Brazilian striker Rafael scored twice as Omiya took a major step toward staying up with a 3-0 win over Urawa Reds, who had Robson Ponte sent off four minutes before the break. Omiya is just above the drop zone in 15th place with 36 points.

Montedio Yamagata moved closer toward remaining in the top flight with 37 points after Katsuyuki Miyazawa scored in a 1-0 win over third-from-last Kashiwa Reysol.

Ryoichi Maeda scored a hat trick to take his tally for the season to a league-leading 18 goals, but Jubilo Iwata squandered a 3-0 lead to draw 3-3 with Nagoya Grampus.