Bundesliga leaders Bayer Leverkusen beat Schalke 04 2-1 thanks to two first-half goals and continue to share the top spot with TSG Hoffenheim.
Kießling netted the opening goal on thirty minutes after preparing work from Renato Augusto, and Helmes added one to his season tally four minutes before the break.
Fred Rutten's side got one back as Kevin Kuranyi headed past Adler in the 85th minute but the goal came too late.
Bayer had to survive part of the match with ten men as Castro picked up a second yellow card in the 67th minute.