In a pulsating affair, Victory took the early lead through Danny Alsopp, before the visitors struck twice within seven minutes through Takahiro Futagawa and Bare to lead 2-1. Rody Vargas squared it up at 2-2 by the break and Allsopp's second on 66 minutes had the home side set for the three points.

But skipper Satoshi Yamaguchi levelled it at three apiece with 21 minutes remaining and Lucas then secured the victory with a header in the 90th minute.

Gamba Osaka, which won consecutive 4-3 games, now have seven points from their three games, while Victory are four points adrift heading into the return match in Osaka on April 23.

The visiting side did not appear on their game early in the match. In the first minute, Nick Ward strolled through the defence to set up Billy Celeski, who at first scuffed his shot then forced a reflex save from Yosuke Fujigaya.

The Osaka keeper wasn't up to the next shot, a fiercely struck effort from Adrian Caceres which he fumbled into the path of Allsopp. The big striker swooped and Victory were 1-0 up after just four minutes.

After weathering the early storm, Osaka pulled level in the 31st minute, when Futagawa found himself in space and decided to try his luck from around 30 metres.

For the second match in a row, Victory were stung by an absolute scorcher, as the ball swerved past Michael Theoklitos and into the top left-hand corner of the net.

Masato Yamazaki tried a similar shot in the 40th minute, prompting a corner which resulted in the Japanese side's second goal. Yashuhito Endo's corner was perfectly placed for Bare to rise above two Melbourne defenders and nod home.

However, the visitors barely had time to celebrate. Celeski won a free kick, and Caceres' pass matched Endo's corner, finding Vargas, who headed the ball home from close range to make it 2-2.

The half ended in frantic manner with Bare twice coming close to scoring, the first hit the bar and then bounced on the line, while the second was cleared by Muscat when headed for the net.

The tempo of the game wasn't quelled by the half time break. On 47 minutes, Matthew Kemp caught Osaka napping, but Allsopp could not convert his cross, knocking it over. Yamazaki responded my charging into the box and shooting just wide up the other end, while Bare could have had a second but headed over.

Gamba Osaka's defence was susceptible to a set piece and Melbourne's third goal came from a free kick from Celeski on 66 minutes. Allsopp's finish with his head was excellent, but it didn't kill off the game.

Within three minutes Osaka had pulled level when Satoshi Yamaguchi leapt highest from a corner and beat a stranded Theoklitos.

The tempo of the match finally relented and there were few genuine chances late in the game. Substitute Kaz Patafta produced a fine save from Fujigaya while Michichiro Yasuda shot wide.

But Osaka proved itself the master of this epic match thanks to a clever cross from Masuda which Lucas was able to head home unattended.

Melbourne Victory 3 (Allsopp 4, 66 Vargas 42)
Gamba Osaka 4 (Futagawa 32, Bare 39, Yamaguchi 69, Lucas 90)
Crowd: 23,857 at Telstra Dome