Yes, it’s legal. Of course, if you destroy all of the defending units in the first combat round, you’re stuck.
@Dukla:
Is it ok to take one territory with one tank and in the same combat move round do blitz with another tank from the same territory{as first tank came}through the NEW territory?{I HAVE 2 TANKS IN ES.EUROPE,1 IS TAKING{unoccupied hostile} UKRAINE AND AFTER I DO MOVE AND BATTLE WITH THE 2nd TANK IN CAUCAS.
Yes, because the blitzed territory is unoccupied.