The Blues twice beat Schalke 3-0 last season and were strengthened over the summer, while the Germans were severely depleted by injury and reeling from their worst Bundesliga start in more than 40 years.
Cesc Fabregas, one of the summer acquisitions, scored his first Chelsea goal after 11 minutes, despite appearing to foul Max Meyer in the build-up.
Eden Hazard was the provider as part of a sensational individual start, as he set about justifying his imminent new contract and his manager's belief that he can be one of the greats of his generation.
It appeared Chelsea would inflict a heavy loss on their opponents, but Mourinho turned away in disbelief after Fabregas blazed over with the goal gaping and the Blues were warned of Schalke's danger when Julian Draxler came close to an equaliser before the interval.
Didier Drogba, playing in the competition for Chelsea for the first time since his penalty secured the 2012 European Cup, was determined to make a mark but failed to convert from passes by Willian and Hazard.
The misses were punished when Klaas Jan Huntelaar struck on the counter-attack after seemingly fouling Fabregas to win possession in the build-up.
Substitute Loic Remy had a shot cleared off the line before Ralf Fahrmann made a brilliant reflex save to deny Hazard and Chelsea.
Source : PA
Source: PA