if there had been no air support from either side on D-day itself the result would probably been the same.
The only Panzer division to attack the beach-heads on D-day was the 21st Panzer Division, and it was easily driven off by a screen of Sherman Fireflys, and 17 pdr Anti-tank guns. In fact the 21st Panzer lost 70 of the 124 tanks it started with on D-Day, almost all to ground combat and artillery.