It depends on many different things. For example you could have a normal duty that ends at minimum rest before check in for that long haul flight, meaning you will get for example a 10 hour rest period and nothing more. That is of course not quite enough to change your body clock. Even worse, depending on company those flight could be done legally with only two pilots (most major airlines augment their crews though). European rules allow it, other rules might be even more relaxed and in the future european rules will be as well.
I could best deal with all night flights by staying awake the previous night and sleeping during the day, however i needed both the previous day and night off to be able to pull that off, not a regular occurrence. Usually for more than half the flight time one of both pilots would nap though, at the end of a grueling summer season that would increase to about 90% of the flight time.