Wasp and newly subdued prey (Eumenidae sp.)

I once again witnessed the struggle for survival in my garden.
Having spotted this Mason Wasp (or thats what I believe it to be) on the flowers it then proceeded to investigate the dead flower heads on a Spirea shrub so as it provided more photo opportunities I followed its movements.
Suddenly it became what can only be described as aggressively excited around a cluster of dead flowers which on closer inspection were bound with silken threads. Over a period of a few minutes the wasp tested the spot for weaknesses and I then saw the occupant , a caterpillar , trying to avoid discovery.
Having evaded capture expertly for a while the wasps persistence paid off and the caterpillar lost its nerve and made a fatal mistake trying to reverse unnoticed out of its nest. This was the chance the wasp needed and it grabbed its prey and dragged it from the woven chamber. After some thrashing about the caterpillar was subdued and its battle to survive lost.
To the victor the spoils as they say.

I was lucky enough to get shots of the entire struggle but here is the final result and one fairly smug looking wasp.