Defending J.League champions Nagoya Grampus cut Gamba Osaka's lead at the top of the table to one point after doubles from Naoshi Nakamura and Jungo Fujimoto sealed a crucial 4-1 triumph over their title rivals at Mizuho Athletic Stadium.
Nagoya got off to a great start as Nakamura slotted home a Keiji Tamada pass in the 11th minute, but their lead was cancelled out 14 minutes later when Korean forward Lee Keun-ho fed Tomokazu Myojin and he made no mistake from inside the box.
Nagoya upped the tempo after the break and took the lead four minutes into the second period when Fujimoto curled a corner directly into the Gamba goal.
Nakamura made it 3-1 in the 68th minute when he fired home from mid-range before Fujimoto again found the target in the 84th minute from Tamada's pass.
Nagoya climbed to second ahead of Kashiwa Reysol, who play Montedio Yamagata at home on Sunday, on goal difference.
"It's a very important victory for us,'' Nagoya manager Dragan Stojkovic said. "It was a big game and very important for us and Gamba, but we played better tactically and absolutely deserved the win. We are now one point behind Gamba. It's very interesting.''
Gamba boss Akira Nishino added: "We should have played a better game but Nagoya nullified the good parts of our performance. Their second goal affected us and we lost our composure after that.
"Every single game counts more from now on and it is important to recover from this defeat.''
Yokohama F. Marinos remain fourth after they were held to a 1-1 draw by Sanfrecce Hiroshima at home.
Masashi Oguro put the hosts ahead in the 75th minute, but Hiroshima substitute David Mujiri equalised three minutes from time.
At the other end of the table, 2007 Asian champions Urawa Reds slipped into the relegation zone after losing 1-0 to Omiya Ardija as Brazilian forward Rafael's 84th-minute goal proved the difference at Saitama Stadium.
Urawa were leapfrogged by Ventforet Kofu, who won 4-0 at Cerezo Osaka with Japan forward Mike Havenaar scoring twice to top the scoring charts on 16 goals.
Bottom side Avispa Fukuoka moved a step closer to relegation after they lost 3-0 at home to Vegalta Sendai. Toshihiro Matsushita scored twice and substitute Yuki Muto also got on the scoresheet.
In Iwata, Kashima Antlers beat Jubilo Iwata 2-1 to win for the first time in four games.
Forward Yuzo Tashiro nodded in Takuya Nozawa's free-kick after 54 minutes to give Kashima the lead, but Hidetaka Kanazono replied 10 minutes later with a header of his own.
Kashima were gifted the winner in the 70th minute, though, when Jubilo defender Shuto Yamamoto attempted to clear Gaku Shibazaki's cross but instead put the ball into his own net.
Vissel Kobe battled back to gain a 1-1 draw against 10-man Shimizu S-Pulse.
Substitute Ryota Morioka cancelled out Shimizu's 55th-minute goal from Eddy Bosnar with a strike five minutes from time. Shimizu were reduced to 10 men in the 77th minute when Calvin Jong-a-Pin received a second caution.