Last season's Champions League runners-up have endured a torrid campaign but have moved to within a point of nearest rivals Borussia Monchengladbach after the success.
Arminia grabbed the lead on 34 minutes through Ansgar Brinkmann but the goalscorer blotted his copybook on 63 minutes when he was sent off for a second bookable offence.
Lucio had earlier hauled Bayer level before the break and the Brazilian defender struck again on 69 minutes.
Hanno Balitsch wrapped up the points two minutes later to breathe renewed life into Bayer's survival aspirations and ensures Arminia are far from safe.
Hansa Rostock scrambled away from the relegation zone after producing a stunning second half display to beat Schalke 3-1.
Schalke's European prospects are lying in tatters after the defeat which leaves them languishing in sixth although they were given the ideal start when Gustavo Varela opened the scoring on 16 minutes.
The game turned on Tomasz Hajto's dismissal on 55 minutes for two yellow cards and Hansa made the most of their numerical superiority.
Rade Prica levelled matters on 65 minutes and Magnus Arvidsson put the hosts in front on 79 minutes with a Rene Rydlewicz penalty on 84 minutes completing the scoring.
Click below for an individual match summary:
Bayer Leverkusen 3-1 Arminia Bielefeld
Hansa Rostock 3-1 Schalke
