Thanks to Francis for spotting this one:)
The first few shots with fill-in flash came out with the background totally dark, blowing out any ambient light. Frustrated, i abandoned the speedlight and tried to shoot with ambient light.
Unfortunately for me, it was overcast and light was scarce, i had to bump up ISO to 640 and open wider to f8 to get a suitable 1/60 handholding shutter speed:)
And just as i thought, natural lighting wins hands down!