Leaders Yokohama F Marinos continued their inconsistent run of form with a 1-1 home draw with Cerezo Osaka - Dutra equalising an early opener from Tatsuya Yamashita - meaning Urawa would have overtaken them with a win in the capital.
However, Mihailo Petrovic's side slumped to a narrow loss at the National Olympic Stadium, with Sota Hirayama grabbing a last-minute winner for Tokyo.
Tomoaki Makino and Daisuke Nasu had drawn Urawa level following first-half strikes from Jang Hyun-Soo and Masato Morishige for the hosts, but striker Hirayama intervened in the dying moments to condemn the title chasers to their second defeat in their last three J.League games.
Meanwhile, Sanfrecce Hiroshima spurned a chance to go second by succumbing to a 2-0 defeat at Kawasaki Frontale, Kengo Nakamura and Renatinho grabbing first-half goals for Yahiro Kazama's in-form side.
Fourth-placed Kashima Antlers failed to take advantage of slip-ups above them as they were beaten 3-0 at relegation-threatened Ventforet Kofu.
Ventforet raced into a three-goal first-half lead thanks to Yoshifumi Kashiwa, Sho Sasaki and Patric, and the AFC Champions League contenders never looked like getting back into the game after the break.
At the other end of the table, bottom-placed Oita Trinita - who have won just once this season - were cut further adrift by their 6-0 thumping at Vegalta Sendai, with defender Makoto Kakuda at the double for the home side.
Second-bottom Jubilo Iwata boosted their own chances of survival in Friday's only match though thanks to an impressive 3-1 win at Kashiwa Reysol, but Shonan Bellmare's hopes of staying in the J.League were dealt a blow with their 1-0 defeat at Sagan Tosu.
Elsewhere, Atomu Tanaka struck 16 minutes from time to give Albriex Niigata a 1-0 victory over Omiya Ardija, while Shimizu S-Pulse ran out 2-1 winners at home to Nagoya Grampus.
