The Ivorian striker, who signed from Evian last month, scored his first goal for Hull after 14 minutes to seal victory in their pre-season friendly on Saturday.
Bruce named Sagbo, Ahmed Elmohamady and Maynor Figueroa in his starting line-up for the clash with the 2. Bundesliga side.
And it was Sagbo who would have an instant impact, finding the back of the net in the early stages with a precise low finish under home keeper Benjamin Kirsten.
Midfielder Robert Koren forced Kirsten into a relatively comfortable save four minutes later, but the first half was largely bereft of chances.
Hull made four changes at the interval, with Sunderland loanee Danny Graham among those to enter the fray.
Graham almost doubled their advantage after 68 minutes, but his powerful effort was parried wide.
The hosts came close to snatching a late leveller when Allan McGregor superbly kept out Marco Hartmann's headed effort one minute from time, but the Premier League side clung on to claim the win.