Agony of Defeat is the 6th episode of Bakugan: Mechtanium Surge. It aired on March 20, 2011.
Dan still refuses to listen to Shun and Marucho when they tell him to take a break from battling. Even though he is still plagued by nightmares about Mag Mel and Razenoid, Dan doesn't mind battling Anubias, with the winner being crowned the official number one brawler of Bakugan Interspace. Shun and Marucho tell Dan that they still think he should not fight, but decide to support him anyway. Dan thanks them and promises to reveal everything after the battle. During the fight, a vision of Mag Mel and Razenoid appear and Dan and Drago think they are fighting them instead of Anubias, causing them to lay waste to the field and endanger the crowd. To make matters worse, Zenthon reappears and everyone learns that Drago created him. Once Zenthon leaves, Dan and Drago's vision disappears and things return to normal. The battle is declared over; Dan is disqualified for illegally using Zenthon (even though it was unintentional) and Anubias is crowned Number One of Bakugan Interspace. Unable to face his fans and shattered bonds between his friends, on top of the fact that Dan can still see Mag Mel and Razenoid, Dan packs up his things to go to New Vestroia with Drago and disappears without a trace.
- In the previous episode, others interfering with a match led to it being declared no contest. Here, Team Anubias interferes with Dan and Anubias' battle, but the match is ruled in Anubias' favor. That is because Dan spawned a Mechtogan before that interference happens.