Brazilian striker Lucas opened the scoring with a deflected shot in the 37th minute and then set up the second for Yasuhito Endo six minutes later.

Michihiro Yasuda volleyed home Gamba’s third in the 68th minute and although Endo had a late goal disallowed, the margin of victory gives Adelaide a mountain to climb in next week’s return match in South Australia.

With Eugene Galekovic still feeling the effects of a groin injury, Gamba tested the Adelaide keeper early on with Myojin sending in a snap shot from 25 yards that was alertly palmed away.

However, the pressure of the home side paid off in the 37th minute as Takahiro Futagawa’s neat pass from the halfway line picked out Lucas in the right channel with only Angelo Costanzo in close attendance.

The Brazilian worked his way to the top of the Adelaide box and although his shot lacked real conviction, it took a deflection off Costanzo and wrong-footed Galekovic as it bounced into the net.

Sota Nakazawa sent a header straight at Galekovic shortly afterwards before Gamba grabbed a second two minutes before half-time after some fine interplay in the Adelaide half.

Hayato Sasaki fed the ball to Lucas and the Brazilian quickly played it to his left to a completely unmarked Endo. The Japan international advanced into the box and fired a low shot across a helpless Galekovic into the far corner of the net.

Travis Dodd crafted his side’s best opportunity early in the second half, sending in a low cross from the right byline that found Robert Cornthwaite. But the Adelaide player failed to make clean contact and the ball eventually went over the crossbar after a scramble in front of goal.

Sasa Ognenovski deflected a shot by Lucas into the side netting but from the resulting corner in the 68th minute, Endo picked out an unmarked Yasuda, whose first-time volley from the top of the Adelaide box bounced past a crowd of players into the net.

Gamba continued to press for more goals and were unfortunate not to add a fourth as substitute Roni fired over in the 75th minute before Masato Yamazaki saw his shot tipped over by Galekovic seven minutes from time.

Endo then fired home a free-kick in stoppage time but the effort was disallowed after referee Abdul Malik Bashir spotted an infringement in the box.