Neither Mainz 05 or FC Koln have been able to make the breakthrough in a tight first half at the Coface Arena.
Park Joo-Ho was an influential figure throughout the first half, and he created the first clear chance for Mainz when he delivered a cross which Johannes Geis headed wide of the post.
Shinji Okazaki was kept on the fringes of the game for much of the first half, but he should have scored the opener when he fired wide after finding space in the box.
However, it was the visitors who finished the first half the stronger of the two sides, and Mergim Mavraj was only denied by a fine save from Loris Karius.
Thomas Kessler then came to the rescue at the other end of the pitch with an impressive stop to keep out Julian Baumgartlinger's header.