Torsten Mattuschka's 63rd-minute penalty sealed the Bavarians' fate. The division's bottom side are now 12 points adrift of the relegation play-off place and potential safety with only three games remaining.
Mattuschka on the spot
The game itself was a tame affair, with neither side creating many chances prior to Tim Erfen's foul on Baris Özbek, which gave Mattuschka the chance to score from the spot and end Union's four-match winless run, sending Regensburg back to the 3. Liga in the process.
Line-ups and statistics