Borussia Dortmund was fortunate to escape with a point after being outplayed by Schalke in Saturday's 0-0 Revierderby draw at Veltins-Arena.
The host — coached by former Borussia Dortmund II boss David Wagner — hit the woodwork twice, while Rabbi Matondo spurned three excellent opportunities.
Schalke also saw a strong penalty claim turned down when a corner appeared to strike Dortmund substitute Thorgan Hazard on the right arm in the second period. Yet it could not find a way past Marwin Hitz, who deputised in goal for Lucien Favre's men with Roman Burki ill.
Salif Sane and Suat Serdar both struck Hitz's right-hand post in a first half that began with Jadon Sancho forcing a superb save from Alexander Nubel — Dortmund's only meaningful chance prior to the interval.
Matondo was then brilliantly denied by Hitz having been played through one-on-one. An offside flag was raised as the save was made but replays showed Matondo was onside, meaning a goal would have stood had he held his nerve.
The Wales winger missed two further presentable chances after the break, either side of Sancho curling an effort wide from 20 yards and Schalke's penalty appeal failing to convince referee Felix Brych.
Dortmund enjoyed its best spell of the game in the closing stages, but neither side could find a goal as they lost ground on new leader Bayern Munich, which is two points above BVB and three ahead of Wagner's men after nine matches.