Kashima Antlers unraveled on the last play of the game as Oswaldo Oliveira's side allowed last-place Shonan Bellmare to equalize in the 95th minute for a 1-1 draw on Saturday.
After controlling most of the 90 minutes, the J. League's best defense fell apart in the dying seconds when Shonan striker Yoshiro Abe pounced on a loose ball inside the box to send the Hiratsuka Stadium crowd into delirium.
Kashima jumped out to a ninth-minute lead through Marquinhos, but failed to put the match out of Shonan's reach despite creating a horde of chances.
The result — the three-time defending champions' third straight 1-1 draw — left second-place Kashima trailing league-leader Nagoya Grampus by eight points with eight games left. Grampus play Albirex at Niigata on Sunday.
"Easy game. We missed many chances," Oliveira said. "They never come. They just come with long balls. I'm very upset because we missed the chance to score two, three more goals. We spoiled it."
Despite the drama, Bellmare were still swimming deep in the relegation zone, eight points away from safety even after 15th-place FC Tokyo's 3-2 loss to Vegalta Sendai.
In other J1 games, former Asian champion Gamba Osaka moved level on 46 points with Kashima after pounding 10-man Omiya Ardija 5-1 at home behind Shoki Hirai and Lee Keun Ho, who each had a brace.
Cerezo Osaka slipped down to fourth, 10 points off the pace after losing 2-0 to streaking Urawa Reds at Saitama. Reds have won four of their last five, and are unbeaten over their last eight games.
In a preview of the Nabisco Cup final, Sanfrecce and Jubilo Iwata drew 1-1 at Hiroshima while Kawasaki Frontale defeated Montedio Yamagata 2-0 at Todoroki Stadium.