The Battle of Qujaga was the final battle of the Peacekeeper/Scarran War. The battle began when the personal vanguard of Emperor Staleek of the Scarran Empire arrived at the planet Qujaga, overpowering the single Peacekeeper command carrier there. Unable to defend his vessel, Captain Miklo Braca sent a distress signal that was received by a the remnants of Grand Chancellor Maryk's battle group -- which was under the command of Commandant Mele-on Grayza. She hoped to turn the tide of the war by killing Staleek, and so her fleet made for Qujaga. A squad of Luxan vessels under the command of Kleeva Ka Jothee also arrived, as did the Leviathan biomechanoid Moya, hoping to protect the Eidelons of the planet.
The Scarrans pursued the Peacekeepers on the ground of the planet -- hoping to destroy the ground forces and kill the Eidelons before they could use their pacifistic powers. The Peacekeepers attempted to protect the surviving Eidelons, but their city had already fallen to the Scarran forces. A group of Luxans and the crew of Moya also made their way to the planet, ultimately joining Braca's forces in protecting Eidelons in their last temple. Though they were able to hold out for some time, eventually War Minister Ahkna led a strike force against them -- with Charrids blowing a hole in the wall of the temple to allow them entry. The Scarrans and Charrids were quickly driven back, and the hole barricaded. Unable to withstand another attack, John Crichton led those taking refuge in the temple into a retreat -- with air support supplied by Jothee's Penetrator. They successfully reached the extraction point offered by Moya, though they sustained heavy casualties including Ka D'Argo. Captain Braca was also wounded in the fighting. The Scarrans had also suffered severe losses -- including that of War Minister Ahkna.
While the battle waged on the ground, another battle waged in orbit. Staleek, believing Maryk to still be alive, had his flagship The Decimator target Grayza's command carrier. She, similarly, was focused on The Decimator. Both sides suffered heavy losses, and fought so fiercely that none of them noticed the activation of a wormhole weapon constructed by Moya's DRDs. The weapon opened a flame-wreathed wormhole with the gravitational pull of a black hole. As the wormhole grew, the fighting ceased as both armadas struggled to escape its gravity. John Crichton offered a deal to all engaged in the battle: either agree to a truce, or he would allow the wormhole to consume the entirety of the Milky Way.
Unable to refuse his offer, they agreed. Crichton destroyed the wormhole and, true to their words, Staleek and Mele-on Grayza met aboard Moya to sign a treaty agreement, overseen by Scorpius and the Eidelons.
Source
The Battle of Qujaga is featured in Farscape: The Peacekeeper Wars Part 2.