Domi Kumbela grabbed the only goal of the game with ten minutes remaining, before Lars Bender's first Bundesliga dismissal reduced the visitors to ten men.
Third for a reason?
Third-place Leverkusen started brightly against the Bundesliga strugglers but, despite dominating possession in the opening stages, failed to create many clear-cut opportunities.
Eren Derdiyok and Simon Rolfes had the only real chances, but Braunschweig's threat was obvious, as Norman Theuerkauf looked to put the hosts in front at the other end.
Braunschweig’s loanee from Leverkusen Karim Bellarabi looked the most likely to create something in the second period and almost gave Torsten Lieberknecht’s team the lead with a stinging effort which flew just over the crossbar.
With nine minutes remaining, Braunschweig went ahead, Kumbela appeared unmarked at the far post to divert Theuerkauf's ball into the back of the net and send the home fans into rapture. Bender was sent off for Leverkusen in stoppage time as Braunschweig held on to record their first home victory of the season.
Line-ups and statistics