Cesc Fabregas scored his first Chelsea goal but was unable to help Jose Mourinho's side to victory in their Champions League group-stage opener as they were held by Schalke.
The Spain midfielder, 27, who joined from Barcelona in the summer, swept in the opener from Eden Hazard's pass.
Missed chances frustrate Mourinho
Didier Drogba shot wide when through before striker Klaas-Jan Huntelaar drove in an equaliser after a counter.
Chelsea's Loic Remy had a shot cleared off the line as Schalke held on.
It was a deserved point for the German side, after an impressive defensive display as Chelsea pushed for a winner in the closing stages.