Schalke's title hopes suffered a major blow on Friday evening after they lost 2-1 to rivals Bochum at The Ruhrstadion.
Schalke had taken an early lead after just eight minutes of the Revier derby when German international Kevin Kuranyi struck.
Kuranyi rose above the home defence to head home Christian Pander's free-kick and send the away fans into raptures.
Gerald Asamoah went close on 20 minutes but was denied by Jaroslav Drobny and that save proved crucial as just moments later Bochum levelled.
Zvjezdan Misimovic - the midfielder, who has already agreed to join Nurnberg - grabbed the goal as he beat the Schalke offside trap before heading past Manuel Neuer.
Schalke retaliated and almost went back ahead with Pander smashing a free-kick against the post - but it was Bochum who crucially grabbed a second just before the break.
Star striker Theofanis Gekas (pictured) was on hand to convert as he broke clear of his markers to fire Marcel Maltriz's cross into the back of the net.
After the break Schalke threatened on numerous occasions with Mesut Ozil, Hamit Altintop and Kuranyi all going close.
Bochum, though, managed to hold on and could even have extended their lead in the final minute, but Misimovic struck the woodwork. Nevertheless the home side still held on for a famous win.
Schalke will now have their eyes on the weekend fixtures with Werder Bremen looking to take advantage as they will move top if they take victory against Arminia Bielefeld.
The three points for Bochum takes them into seventh in the table.