Stuttgart suffer home defeat to Freiburg
Johannes Flum grabbed the winner after 24 minutes for the visitors, who are enjoying a sparkling season and moved up to sixth.
Stuttgart were joined on 16 points from 20 games by bottom side Borussia Moenchengladbach who stunned Eintracht Frankfurt five minutes from time with a goal from Belgian Igor de Camargo to win 1-0.
Both teams are three points adrift of Cologne who occupy the relegation play-off place.
Stuttgart, suffering their first defeat since the league resumed after the winter break, were dominant in the second half but with Brazilian Cacau missing, they lacked a cutting edge against Freiburg.
Sven Schipplock failed to beat Freiburg keeper Oliver Baumann with a curling shot from the right midway through the second period and Stuttgart's Martin Harnik struck the post a minute from time.
Leaders Borussia Dortmund crushed hosts VfL Wolfsburg 3-0 on Saturday to go 11 points clear at the top, with Bayer Leverkusen second on 39. Bayern Munich battled back for a 3-1 win over Werder Bremen to move up to third on 36.