How to Defeat the Widowmaker and earn 'In This Together' in Resistance 3 on the PS3

This guide makes beating the Widowmaker in Times Square easy enough, so picking up the 'In This Together' Resistance 3 trophy shouldn't be that hard either right? If you head to the location of the Chimera you kill at the beginning of the fight and then walk towards the edge of the map, you can actually fight the Widowmaker without it being able to hit you.

Just to be clear, this is the Widowmaker boss fight that occurs in Chapter 17.