Shinzo Koroki notched in the fifth and 55th minutes - either side of Genki Haraguchi's strike just before the half hour - as the hosts looked to run rampant.
There was no chance of a comeback although Hiroki Mizumoto did at least grab a consolation for Sanfrecce with his effort in the final minute.
However, their defeat means that Yokohama F. Marinos are now breathing down their necks after Marcos Marquinhos' brace gave them a 2-1 win at struggling Shonan Bellmare.
Marquinhos opened the scoring in the 10th minute although substitute Ryota Kajikawa levelled proceedings before the hour.
Marquinhos and Yokohama would have the last laugh, however, when the Brazilian striker netted from the penalty spot in the 64th minute.
Omiya Ardija slipped from second to fourth in the standings after Yasushi Endoh's 50th-minute strike gave fifth-placed Kashima Antlers a 1-0 victory.
Kazuma Watanabe scored in the 37th and 47th minutes - the second from the penalty spot - as FC Tokyo eased past bottom side Oita Trinita 2-0.
Kengo Kawamata scored twice to help 10-man Albirex Niigata to a 3-1 win against Shimizu S-Pulse.
Kawamata netted in either half, while substitute Hideya Okamoto ensured victory in the final minute after Dzenan Radoncic had halved the deficit. It meant that Jin-Su Kim's dismissal in the final minute had little impact on the outcome.
Nagoya Grampus Eight were made to work hard to see off relegation-threatened Jubilo Iwata 3-2.
Yoshizumi Ogawa opened the scoring for Nagoya and although Yamada levelled, the visitors pulled ahead again through second-half strikes from Joshua Kennedy (penalty) and Keiji Tamada, which meant Hidetaka Kanazono's effort late on was mere consolation for Jubilo, who remain four points adrift of safety.
Masato Kudo scored in either half as Kashiwa Reysol claimed a 2-1 win over Sagan Tosu, who set up a tense finale when Ricardo da Silva Nilson scored two minutes from time. Their failure to find a leveller means they lie just one point above the relegation zone.
Goals in either half from Rodrigues Wilson and Toshihiro Matsushita helped Vegalta Sendai edge out Kawasaki Frontale 2-1, with Calixto Renato's leveller not enough for the visitors, while Akito Kawamoto's 66th-minute strike gave Vantforet Kofu a 1-0 win at Cerezo Osaka.