Duel in Jibalra

"The Darksaber? Yes, a lightsaber. A strange one at that. It belonged to a late warrior named Pre Vizsla, vile by even my standards, and I knew him well. His lightsaber crossed with my beskad during our civil war in the abandoned city of Jibalra after both of our forces were decimated in a skirmish. I drove my beskad into his side, but didn't stay to see the results. Of course, the man survived, and did for over another decade. But that thing doesn't matter to most of us, does the Queen of Naboo's scepter represent your Chancellor's leadership?"

- Naastau to Luke Skywalker

During the Mandalorian civil war (c. 32 BBY), the Mandalorian warrior Naastau led a small band against Pre Vizsla and his Death Watchmen in the abandoned dome city of Jibalra on Mandalore.

Overview
After both Naastau and Vizsla's warriors were both wiped out in the ensuing skirmish, the two engaged eachother in single combat - Naastau armed with a beskad sword and Vizsla with the Darksaber. After a lengthy engagement, Naastau managed to impale Pre through the torso with his sword before fleeing, an injury which Pre would just barely survive.

Naastau would later recount the story of the duel in 6 ABY to Luke Skywalker aboard his casino station, after Skywalker inquired about the nature of the weapon.