Ingolstadt offered a sign of what was to come on a disastrous day for their defence as Hannover took the lead in just the fifth minute when Marcelo found the space to head home from a corner.
The lead was quickly doubled as Kenan Karaman eased past a couple of challenges before turning in the box to find the unmarked Leon Andreasen, who was left with the simple task of nodding into an empty net.
A third goal arrived in spectacular fashion midway through the first half as Karaman collected a long ball forward before capitalising on the space in front of him to find the top corner from 25 yards and leave the visitors stunned.
Hannover remained in control after the break, but chances were difficult to come by until Ramazan Ozcan got a strong hand to Artur Sobiech's header to prevent the visitors from falling further behind.
It was the hosts who added gloss to the scoreline late on as confusion in the box allowed Uffe Bech to send a loose ball past a helpless Ozcan as Hannover moved four points clear of the bottom three.