A compression test is a fairly poor indicator of such problems. It's good to use as a comparative tool - which is what you've done - but past that the results are essentially meaningless. Trying to use it to pinpoint the issue is generally a fruitless endeavor.
A leakdown test, which uses compressed air to pressurize the cylinders individually, will not only tell you the health of the cylinder, but usually where the leak is coming from. With the piston @ TDC on the power stroke, if your leakdown number is excessive and air is heard in the intake tract, it's likely an intake valve. If the sound of air is heard in the exhaust - exhaust valves. If air is heard rushing out of the crankcase (oil fill), it's likely the rings. And if it's the head gasket you'll usually see bubbles rising in the radiator.
This isn't a 2-stroke. I'd personally find it very surprising if you holed a piston. Not impossible, but unlikely. Especially when the other 3 cylinders are GTG.
Regardless of what the issue is, if your compression test is being performed correctly with properly-functioning equipment, then you've got a problem that's going to necessitate, at a minimum, pulling the head. No amount of conjecture is going to change that. That is, of course, assuming the performance decrease matches up with your finding of zero compression. If your comp is really that low (with all other cylinders being good), then you should notice a very significant difference in power & response.