Boomsticks!
Widow QFI, landed in a lobby with a QMI with BW, a demolisher with Typhoon/BW, and a Paladin; UUG turned out to be Giant/Cerberus. Turns out that arc grenades are perfect for setting up headshots on phantoms and dragoons, and patiently waiting for the engineers to set their turrets down before sabotaging them will never, ever get old
... that, and slipping by the frontlines, to sabotage the Atlas in the back, of course 
This was probably my first gold match where I used zero consumables, which speaks for a solid team effort... and who needs missiles with all that firepower?
Final wrinkle, on extraction the demolisher dropped the pylon on top of the stairs by the control room, then slipped down and kept all the enemies staggered, allowing me to set up shop up there and pick heads off... turned into one of the easiest extraction waves I have ever had against cerberus.