Confrontation in the Republic Executive Building

"Master Windu; I take it Master Kenobi has destroyed General Grievous, then. I must say you're here sooner than expected. 'In the name of the senate of the Galactic Republic, you are under arrest, Chancellor.' 'Are you threatening me, Master Jedi?' 'The senate shall decide your fate.' 'I am the senate!' 'Not yet, Lord Sidious.' It's treason, then."

- starwars:Star Wars Episode III: Revenge of the Sith

The Duel in the Chancellor's Suite was a lightsaber duel between the Dark Lord of the Sith, Darth Sidious, and Jedi Masters Mace Windu, Kit Fisto, Saesee Tiin, and Agen Kolar in the Chancellor's Suite of the Republic Executive Building.