Julian Draxler scored a stunning goal to earn Schalke a 1-0 victory at Basel in a Champions League Group E game that was briefly interrupted by a Greenpeace protest.
In the fifth minute activists dropped down from the stadium roof on cables to unfurl a banner criticising Russian state-owned Gazprom, sponsors of Schalke and the Champions League.
A spokesman for organisers UEFA said the incident would be reported and disciplinary proceedings could be launched.
Schalke fans also used pyrotechnics, which are banned by UEFA, at the start of the game.
The only goal came when a partially cleared corner fell to Draxler 25 metres out and, although it bounced to him at an awkward height, he struck a superb rising shot into the top corner in the 54th minute.
Victory gave the Germans six points from two games and a three-point lead over Basel and Chelsea who defeated rock bottom Steaua Bucharest 4-0 in Romania.
Schalke coach Jens Keller was almost as happy that his defence kept a clean sheet after they had conceded 16 goals in seven Bundesliga outings including a 3-3 draw at Hoffenheim on Saturday.
He said he could not understand why the 2011 semi-finalists concentrated so much better in the Champions League.
"We defended very well, the forwards helped the defenders and tactically we were very good throughout the game," Keller said after Schalke chalked up their second clean sheet in the competition.
Draxler, 20, produced several other moments of breathtaking skill including one near the end where he nearly added another goal after a mesmerising dribble on the left.
Basel, already playing their 18th game of the season and their sixth in Europe, lacked the finishing touches in the final third of the pitch to match their neat approach work.
Egyptian forward Mohamed Salah showed only flashes of his sublime talent as the Swiss league champions, who reached the Europa League semi-finals last season, failed to build on their stunning 2-1 win at Chelsea last month.
"Things didn't work for us in the final 30 metres," said Basel coach Murat Yakin. "We must learn to do better in standard defensive situations. It wasn't one of our best days today."
Kevin-Prince Boateng missed an early chance for Schalke when he dragged his shot wide of the post after a mis-hit clearance by defender Fabian Schaer.
Draxler failed to find the target after getting into a good position and a poor first touch from Jefferson Farfan meant another flowing move came to nothing for the visitors.
Schalke went close again when Roman Neustaedter headed wide from a free-kick just before the break and he also struck the bar with a dipping 30-metre effort after the restart.
Basel pushed forward after the goal and Schaer saw a dipping shot go narrowly wide from long range while a Giovanni Sio effort was parried by keeper Timo Hildebrand.
Draxler nearly added a second goal after a mazy run that ended with him shooting over the crossbar.
THE MATCH IN A TWEET