Leverkusen went into the game at the BayArena knowing a win would open up a three-point lead over nearest challengers Wolfsburg, who could only draw 2-2 with Freiburg earlier on Saturday.
But, in the hosts' first game since announcing the appointment of Roger Schmidt as coach for next season, interim boss Sascha Lewandowski wasted an opportunity to take another step towards sealing a place in next season's UEFA Champions League.
Attacking midfielder Gonzalo Castro re-established Leverkusen's superiority 10 minutes prior to the interval, but a resilient Dortmund - whose build-up to the game was overshadowed by rumours linking coach Jurgen Klopp with the vacant position at Manchester United - earned a share of the spoils four minutes later through Marco Reus' penalty.
Dortmund keeper Roman Weidenfeller produced a fine save to keep out Stefan Kiessling's volley, but the hosts kept the pressure on and Bender reacted quickest to a rebound after the striker hit the crossbar, finding the net despite the best efforts of Nuri Sahin on the line.
The hosts failed to build on that lead in an open first half, and Dortmund duly levelled matters just before the half-hour mark when Kirch turned Reus' left-wing free-kick into the top corner with an improvised backwards header.
Parity remained for just six minutes, as Castro restored Leverkusen's advantage by heading into the bottom corner following a well-worked move involving Son Heung-Min and Kiessling.
