Starting the fight over control of Uptown district (District Showdown) will become possible only after lowering D.U.P. control indicator to 30%. Head to the place marked on the map with a phone icon (large billboard on the roof) and make a call.
During the battle for control over the district in question, once again you will have to face mainly heavily armored soldiers, whom you have probably fought while attacking the two mobile command centers. As a reminder, it is advisable to keep a safe distance and rely on strong ranged attacks. There is also a group of standard D.U.P. soldiers to eliminate, but they should not cause you too much trouble.
Rewards for taking control over Uptown :
- Fast travel option
- Getting rid of all D.U.P. soldiers in the area
- A unique outfit for Delsin - X-Bone (you can change it in one of the menu windows opened by pressing Options button)