Hiroshima were held 1-1 away from home by the league's bottom side Oita Trinita, who cancelled out Tsukasa Shiotani's 57th-minute opener when substitute Yasuhito Morishima netted in the 78th minute, four minutes after coming off the bench.
Yokohama F Marinos dropped to second after stumbling to a 2-1 defeat at Kashima Antlers, letting the lead that Marcos Marquinhos gave them in the 19th minute slip away as Yuya Osako equalised after 69 minutes and then grabbed his second goal nine minutes later. Kashima climbed to fourth place.
The failure of the top two to impose themselves on the road enabled Urawa to close to just a point behind both.
While Hiroshima and Yokohama have 44 points from 22 games, Urawa now have 43 thanks to first-half goals from Yosuke Kashiwagi and Shinzo Koroki against Shimizu S-Pulse, Kashiwagi opened the scoring in the seventh minute, and Koroki sealed a 2-0 win when he plundered the second 20 minutes later.
Second-bottom Jubilo Iwata and mid-table FC Tokyo drew 0-0, and Koya Mizunuma gave Sagan Tosu a 1-0 victory over Vegalta Sendai with a 26th-minute goal.
Cerezo Osaka looked set to win at Nagoya Grampus Eight when Yoichiro Kakitani broke the long deadlock in the 87th minute, however almost immediately substitute Kisho Yano plundered a leveller.
Albirex won 2-1 at home against Kawasaki Frontale, goals from Kengo Kawamate and Hideya Okamoto countering one from Yoshito Okubo, while Vantforet Kofu prevailed by the same margin at Shonan Bellmare. Anderson Patrick and Kensuke Fukuda netted for the victors, with Kazunari Ono the marksman for the home side.
Omiya Ardija slipped to sixth place, beaten 3-2 on their own pitch by Kashiwa Reysol.
Junya Tanaka netted twice in the opening half hour to put Kashiwa in apparent control, but Zlatan Ljubijankic and Daigo Watanabe hauled the sides lelvel, only for Masakatsu Sawa to pouch a 65th-minute winner.