Defending J-League champions Kashima Antlers crashed to a 2-1 defeat to Kyoto Purple Sanga on Wednesday, failing to extend their lead in the standings.
Kashima midfielder Takuya Nozawa cancelled out Atsushi Yanagisawa's opener with a right-footer in the 21st minute, but Kyoto's Yuto Sato fired home a 30-yard shot in the 84th minute to seal the win.
Kashima now have nine wins, four draws and four defeats for 31 points, two points above Asian club champions Urawa Red Diamonds, Nagoya Grampus and Gamba Osaka. They are followed by Kashiwa Reysol and Albirex Niigata with 26 points.
"We lost two goals because of our mistakes. On the contrary, we couldn't score when we had a chance. It often happens in football, and it happened today," said Kashima's Brazilian coach Oswaldo Oliveira. "I think we rushed a little too much."
Osaka were held to a 1-1 draw by FC Tokyo after they failed to keep the early lead secured with Brazilian striker Lucas' goal in the sixth minute. FC Tokyo's Yuhei Tokunaga struck home an equalizer 13 minutes later.
In other games, Vissel Kobe edged past Yokohama Marinos 1-0 thanks to Korean midfielder Kim Nam-Il's goal in the 59th minute. Consadole Sapporo and Oita Trinita fought it out to a goalless draw, while bottom placers JEF United Chiba drew with Albirex Niigata 2-2. On Thursday, Urawa were to play Tokyo Verdy, while Nagoya will face Jubilo Iwata.