Yasuhiro Higuchi’s men had been sat just behind Sanfrecce Hiroshima on goal difference after their weekend defeat to Kashima Antlers, but their impressive win over Urawa has now given them breathing space.
The result, Urawa's first loss in three games, came after Marquinhos netted his 16th goal of the season and 35-year-old Shunsuke Nakamura fired home a brace.
Mihailo Petrovic’s team now sit four points off the league leaders and one shy of Sanfrecce, who fell to a shock 2-0 defeat at Ventforet Kofu.
An early goal from midfielder Yoshifumi Kashiwa left the travelling side with some work to do, and they were unable to get a foothold in the game as Kazunari Hosaka sealed the points in the 52nd minute.
Kofu's second win in a row moved them further away from the relegation zone, with the league's bottom two, Oita Trinita and Jubilo Iwata, also losing out to Nagoya Grampus and Albirex Niigata respectively.
Rock-bottom Oita were edged out 2-1 after going ahead through Riki Matsuda, while Jubilo let a two-goal advantage slip as Kengo Kawamata's double, as well as efforts from Yuta Mikado and Roger Gaucho secured a 4-2 win for Albirex.
Omiya Ardija's rotten form continued as they lost their eighth game in a row, 2-1 to Kawasaki Frontale.
Tsutomu Ogura's outfit had looked like title challengers earlier in the campaign, but their terrible run has seen them slip out of contention for an AFC Champions League spot.
Kashiwa Reysol, on the other hand, are the league's form team, having gone unbeaten in their last nine outings.
Their latest success came courtesy of a 5-2 win over Shonan Bellmare, Kenta Kano and Masato Kudo each grabbing braces, while Junya Tanaka scored his third goal in his last two games.
Elsewhere on Wednesday, Vegalta Sendai and Cerezo Osaka played out the only draw which ended 1-1, while Shimizu S-Pulse and Sagan Tosu both clinched marginal victories.
Shimizu earned their 4-3 win over Kashima Antlers with a late effort from Toshiyuki Takagi, which marked his hat-trick, while Sagan Tosu’s 3-2 win over Tokyo came courtesy of a 85th-minute goal from Yohei Toyoda.
