The Red Devils will meet LDU Quito of Ecuador in the final on Sunday.
United boss Sir Alex Ferguson was quick to praise his keeper despite the Dutchman conceding three goals and thought that his side were deserved winners.
"It was a terrific match, an amazing game, the people got their money's worth," Ferguson said.
"The football from both teams was very good. For me Edwin Van der Sar was our best player, his saves helped secure the victory for us.
"We are in the final and I think we deserve to be there."
The Reds chief also praised the opponents, "Their movement on the ball was very good and it shows you much Japanese football has improved."
As for two-goal Rooney, "His movement, strength and penetration are very good," Ferguson said. "The goal that really killed them was the third one."