Table-topping Urawa went into the weekend's first-versus-second clash in Saitama knowing that three points would seal their long-awaited championship win, while a draw would put them on the verge of glory with just two games remaining.
However, the hosts were beaten courtesy of goals from Sato and Kurata, with the first coming after 87 minutes when Lins squared for Sato to finish following a quick breakaway.
And the points were sealed for Gamba soon after when Karata fired home after a quick stepover to beat his man.
Gamba now trail the leaders by just two points going into the final two games, with Reds urgently needing to steel themselves before visiting fourth-place Sagan Tosu next week.
Mathematically, Sagan remain in with a chance of winning the title - trailing Urawa by five points - but they will likely be focused on stealing into the AFC Champions League places.
Michihiro Yasuda's 83rd-minute goal at Tokushima Vortis kept Sagan a point behind Kashima Antlers in third, with Toninho Cerezo's side condemning Kawasaki Frontale to a third consecutive league defeat.
At the other end of the table, Cerezo Osaka salvaged a point against Vegalta Sendai in a 3-3 thriller to keep their survival hopes alive.
Having fought back from 2-0 down, Cacau's injury-time equaliser cancelled out Ramon Lopes' earlier effort to keep Vegalta in the relegation mix-up.
Shimizu S-Pulse's hopes of staying in the J.League remain in the balance, despite twice fighting back to gain a 2-2 draw against Nagoya Grampus, while Omiya Ardija stay 16th afer a 2-1 reverse at home to Kashiwa Reysol.
Ventforet Kofu were able to secure their top-flight status for another season, however, as Hideomi Yamamoto and Ryohei Arai on target in their 2-0 win over Sanfrecce Hiroshima.
That leaves four teams battling to avoid joining Tokushima in the J2 League while, elsewhere, there were wins for Yokohama F Marinos at Vissel Kobe and Albirex Niigata against Tokyo.