Ingolstadt started the second half of the Bundesliga season the way they had started the first, with a 1-0 win over Mainz.
Moritz Hartmann hit the crossbar for the hosts in the 20th minute before giving them the lead from the penalty spot after Danny Latza handled the ball inside the penalty area.
Mainz lacked invention to carve out an equaliser as Ingolstadt fought hard to ensure the points would remain in Bavaria, and they would hold on to their proud record of never having slipped into the bottom third of the Bundesliga.
Saturday's win lifts Ralph Hasenhuttl's men above Hamburg into 10th, just a point behind Mainz and closer to a place in Europe than to the relegation zone.