Attack on the Pro-bending Arena

The Attack on the Pro-bending Arena was one of the early battles of the Equalist revolt. It occurred at the Pro-bending Arena when undercover Equalist agents entered the arena and began attacking the metalbending officers that guarded the place once the White Falls Wolfbats won the tournament final in order to make spectators hear Amon's speech about equality and show them his ability to take bending away, ensuing a battle at Lin Beifong and Avatar Korra's attempts of halt.

History
While training for their championship match, the Fire Ferrets hear Amon threaten the United Republic Council to cancel the Pro-bending championship match. Korra and her teammates rush down to City Hall, where the entire council has decided that the match should be canceled. The decision was about to be made final when Chief Beifong arrives and convinces Tarrlok and the rest of the council to allow the game to go on, promising that she and her metalbending cops would be at the match to protect the people.

Meanwhile, the Lieutenant informs Amon that the council has defied his warning, to which Amon replies that everything is going according to plan.

At the Pro-bending arena, Lin has her metalbending cops scour the entire arena for anything strange, but they find nothing. The championship match begins, and the Wolfbats break many of the rules, such as having an illegal headshot and bending a disk from their opponents' zone, and ultimately win the match, having apparently payed off the referees.

Battle
After Tahno and the Wolfbats win the championship, Equalists appear in the audience, pulling masks and gloves out of their popcorn. They use these gloves to electrify the metalbending cops, followed by Lin and Tenzin.

The Lieutenant appears under the arena by the water, where the Fire Ferrets have yet to swim out after being knocked out, and zaps the water with his electrified kali sticks, knocking out Korra and her teammates. He then ties the Fire Ferrets to an arena support.

Amon and multiple Equalists approach Tahno and the Wolfbats on the arena. The Wolfbats resist, but are quickly captured by Amon and his troopers. Tahno offers Amon the championship pot in exchange for getting to keep his bending, which Amon ignores. Amon takes away the bending of each member of the Wolfbats, and the Equalists toss them into the water below. Amon gives a speech to the audience, using the Wolfbats' breaking of the rules as another reason benders are corrupt and evil and warns any bender in the audience to stay out of his way or suffer the consequences. He then addresses his followers by introducing the electrified gloves to his followers. He then announces that the revolution has begun. An equalist airship appears above the stadium, and many ropes with platforms at the end smash through the glass dome above and fall near the Equalists, which they use to depart.

Meanwhile, the Fire Ferrets regain conciousness, and discover that they are tied up. They spot Pabu nearby and call him over. Bolin speaks to Pabu, telling him to bite through the rope, which Pabu eventually does. Lin and Tenzin also wake up, noticing Amon and the Equalists escaping.

After Pabu finishes biting the rope, Korra makes a water cyclone to boost her up to the Equalists, but runs out of water before she is high enough. Lin uses her metalbending cables to catch Korra. Lin continues to metalbend their way onto the roof of the arena, where the two engages in a battle with the Lieutenant and multiple Equalists. Lin uses metalbending to prevent more Equalists from coming, and then sees a chance to get onto Amon's airship. She takes this opportunity while Korra continues to fight the Lieutenant. Korra eventually knocks the Lieutenant off the roof, but the glass beneath her breaks, and Korra once again starts to fall. Lin notices and abandons her chance to attack Amon, and uses her metal cables to save Korra from falling again.

Back on the ground, Korra thanks Lin for saving her as the Equalists fly away on their airship. Bolin and Mako rush to Korra, expressing their relief that she is alright. Tenzin then states that "Republic City is at war."

Aftermath
Due to the destruction of the stadium, Mako and Bolin can no longer live there, but are offered a place to live at the Sato estate by Asami, and later a place at Air Temple Island by Korra.

Tarrlok is angry with Lin, saying that she has failed Republic City, and that Republic City's law enforcement needs a new leader. This, in addition to the Battle at the Equalist factory, leads to her resignation as the Chief of Police.