The Duel on Imperial City was a lightsaber duel that took place between Typhuss James Kira and Vader, during the Federation-Der'kal War in 2386.
Typhuss was ultimately outmatched against Lord Vader and was defeated by him.
At the end of the duel, Typhuss managed to escape from Vader with help from John Martin, Jyn Erso, Sarah Mackenzie and Natalie Teeger.