Both teams came into the game off the back of wins and that was reflected in the line-ups. 1860 remained unchanged, while Jens Keller opted to bring in Redondo for Adrian Nikci.
Redondo runs the show
That decision was immediately justified, too, as he created the opening goal. Damir Kreilach's ball over the top of the defence was collected by Redondo, as he managed to work his way around Fanol Perdedaj. After that, his task was simple; a routine cross to the back post was poked home by the waiting Skrzybski.
It was a tight game in every respect but the game continued to go end-to-end, with neither side able to take full advantage. Union still held the upper hand and had a great to chance to make the most of a breakaway, but instead of feeding in Skrzybski, Kreilach opted to shoot and his effort went well over the bar.
1860 then responded and did so with real purpose. Daniel Adlung among those to rain down shots on Jakob Busk's goal, before they were awarded a penalty. Adlung's free-kick caught the hand of Collin Quaner, and Florian Heft rightly pointed to the spot. Michael Liendl stepped up and duly converted to level the scores.
After that it was largely anyone's game, as both continued to pile forward in search of the advantage before half-time. The hosts were limited to shots from range, while Union came closer still. A poor clearing header from the Lions' defence fell for Redondo, whose volley rattled the crossbar from 20 yards; Zimmermann was well beaten.
Redondo would not be denied his goal, though, as his determination earned his side a half-time lead. It came from a Milos Degenek error, as the Australian defender misjudged a back-pass and allowed the winger to sneak through on goal before finishing coolly past Jan Zimmermann to restore his side's advantage.
1860 dominate the second period but can't grab an equaliser
The second half didn't begin as Keller would have wanted, as Kosta Runjaic's side came out in search of another equaliser. Fabian Schönheim, who had been booked in a case of mistaken identity for the first-half penalty, was shown a second yellow; much to his surprise, with Union reduced to 10 men the pressure ramped up further.
Liendl was first two go close, as the resulting free-kick fell his way and was smashed just inches over the crossbar. They came again and this time went even closer, with Maximilian Wittek afforded the time and space to dart forward before his rasping, dipping strike cannoned off the outside of the post to safety.
By the hour mark, Union were resigned to being under the kosh and had set about building the trenches. Michael Parensen replaced Felix Kroos in a defensive change, but that couldn't halt their hosts. Levent Aycicek shot was saved by the very busy Busk, before Wittek's cut-back was forced clear after goal-mouth scramble.
Quaner then had two late chances to put the game beyond doubt in the latter stages as things became stretched, but the in-form striker failed to finish either chance. That didn't matter, though, as his defence had done enough to some how survive the onslaught and come away with an incredible away win.