Frankfurt had a good opening early on when Jan Rosenthal headed against the post from a cross.
The first half failed to produce many chances for either side, but the second 45 minutes saw the game open up.
© Getty Images
Leverkusen came back at their opponents and Giulio Donati fired in a low shot that Trapp did well to save at his near post.
Kiessling then sent in a cross, but it was just too powerful for Omer Toprak and his header drifted wide.
The hosts were doing their best to find an equaliser, but Trapp in the Frankfurt goal was proving hard to beat. On this occasion some good passing set Kiessling away in the box, but his shot was pushed away before Jung got across to block the rebound.