But Jubilo were forced to come back from a goal down after Japan international Toshihiro Hattori, later sent off, cancelled Yoshiteru Yamashita's opener with a penalty in the 28th minute.

Nishi clinched the win in the 22nd minute of extra time, for Jubilo to open up a nine-point lead on the standings with a tally of 31 from 12 games.

They can now seal the first-stage title by beating struggling Yokohama F Marinos on July 7, following a one-week break in the J-1 schedule.

Meanwhile, South Korean striker Choi Yong Soo scored both goals as JEF United Ichihara beat Shimizu 2-0 at home to move above S-Pulse into second place, nine points adrift of Jubilo.

Shimizu have 20 points but still have a game in hand on the top two teams.

Former S-Pulse boss Steve Perryman got off to a winning start in his new job as assistant manager of Kashiwa Reysol, the away side trouncing Nagoya Grampus Eight 4-1 away in a one-sided match at Mizuho Stadium.

Goals from Japan internationals Atsushi Yanagisawa and Koji Nakata lifted last season's treble winners Kashima Antlers to a 2-0 win at home to Yokohama, while Yuichiro Nagai scored twice as Urawa Reds beat visiting Consadole Sapporo 2-0.

At the foot of the table, Tokyo Verdy moved up to 14th place after a sudden-death goal from Keiji Ishizuka earned them a 1-0 victory at home to Vissel Kobe.

Cerezo Osaka, meanwhile, slipped to the bottom of J-1 after a 2-1 home defeat to FC Tokyo.