After a fantastic effort midweek against the Chinese champions, Gamba accounted for Jubilo Iwata 4-1 at the Expo '70 Stadium.
Yasuhito Endo opened the scoring in the 36th minute, before Dong Hyuk Park added a second in the 55th.
Two minutes later, Gilsinho gave the visitors a glimmer of hope but it was all but over when Endo managed his second just past the hour-mark.
A 67th minute goal from Leandro ended the rout and put Gamba back on top of the J-League table.
They now face a huge test against FC Seoul in the ACL on Tuesday night at the Seoul World Cup Stadium.