Cologne picked up their first win of the season at Stuttgart whose fans made their dissatisfaction clear to coach Armin Veh.
Yuya Osako scored his first goal in the Bundesliga to give Cologne the lead midway through the first half, and Anthony Ujah added a second before half-time.
Stuttgart's response was insufficient with the fans venting their anger at the prospect of another season of struggle, this time under the guidance of the coach who led them to their last Bundesliga title seven years ago and is back for a second spell.
Stuttgart looked lively enough in attack, but for all their endeavours their defence let them down twice in the first half.
The first mistake came in the 22nd minute and allowed Osako to make his mark.
Sven Ulreich pushed Miso Brecko's cross past Antonio Rudiger and into the path of the Japanese forward, who accepted the gift from close range to open his account for the team.
Rudiger, who earlier in the week had spoken of his ambition of playing in the English Premier League, would not have done himself any favours in front of watching scouts when he completely misjudged Kevin Wimmer's long ball forwards, letting it fall to Ujah who unleashed an unstoppable shot into the bottom left corner from 25 yards.
The hosts were inevitably sent into the dressing room at half-time with whistles from the fans ringing in their ears.
After being knocked out of the DFB-Pokal in the first round and drawing 1-1 at Borussia Monchengladbach last weekend, the fans' patience was already wearing thin.
Their team tried to respond in the second half, but aside from a dipping Daniel Didavi effort, which was pushed over the bar by Timo Horn, they never went close to pulling a goal back.
Cologne intelligently played on the counter-attack and they almost added a third when Daniel Halfar lobbed a shot just wide of the goal.