Brazilian striker Lucas scored in the 4th and 15th minutes Wednesday as Gamba Osaka completed a 5-0 aggregate win over Adelaide United in the Asian Champions League final, giving Japan back-to-back continental titles. Osaka beat defending champion and Japanese J-League rival Urawa Red Diamonds in the semifinals and then dominated both legs of the final, winning 2-0 here Wednesday after a 3-0 victory in the home leg last week. Despite the loss, Adelaide - the first Australian club to reach the Asian club championship final - qualified for the Club World Cup against the likes of Manchester United next month because host Japan was guaranteed of having a team in the competition. Gamba earned a spot as Asian champion. Gamba coach Akira Nishino said his team was confident going into the match but still surprised by the strength of its start. “There was a lot of pressure, but I'm very happy for us to receive this trophy,” he said. “We started a lot smoother than I expected. I expected a lot of pressure but we were very aggressive.” Adelaide's best chance of a comeback from the first-leg deficit was to keep a clean sheet and score three to force extra time, but that plan was ruined early when 17-year-old goalkeeper Mark Birighitti parried Hayato Sasaki's long-range shot and Lucas pounced on the rebound. The away goals rule meant Adelaide faced the enormous task of getting five goals, and the contest was effectively ended in the 15th when good lead-up work in midfield put Lucas through on goal. He nudged the ball with the outside of his right boot beyond the onrushing Birighitti, who was deputizing for Adelaide's suspended first-choice ‘keeper Eugene Galekovic. Adelaide had limited chances, finding the back of the net in the 27th minute but it was called back for offside, and Kristian Sarkies narrowly failed to make contact with a Travis Dodd cross in the 51st minute. “It seemed like they had 15 players out there,” Dodd said. “They found space, their movement off the ball was unbelievable and they're easily the best team we've played in this competition. “It's been a long physical and mental journey. It's bitterly disappointing to lose any game but a final is especially bad.” Adelaide will play New Zealand's Waitakere United in the opening game of the Club World Cup next month, and if it wins, it will face Gamba again, with the victor of that match to take on Manchester United in the semifinals.