Mohamed Zidan scored his first Bundesliga goal this season on Saturday but couldn't save Werder Bremen from a shocking 3-2 defeat against Stuttgart. The Egyptian international striker lofted an ice-cool volley over the goalkeeper in the 33rd minute to put his side two up after Stuttgart defender Roberto Hilbert converted the ball into his own net as early as the fourth minute. But Hilbert made up for his mistake in the 38th minute before Pavel Pardo and Luis Gomez found the net as Stuttgart stormed back to secure the three points. The defeat put Bremen in seventh spot with six points, leading Stuttgart on goal difference. It also capped a bad week for the German League runners-up as they lost 2-0 to Chelsea in the Champions League. Elsewhere, Germany double winners Bayern Munich slumped to a 2-1 defeat against Arminia Bielefeld. Bayern grabbed the lead through newly-signed midfielder Mark Van Bommel who buried the ball home in the sixth minute. Artur Wichniarek equalized in the 25th minute and Jonas Kamper curled a stinging free-kick home as Bielefeld pulled off the biggest upset in the Bundesliga so far. Bayern, who produced a 4-0 drubbing of Spartak Moscow in Europe earlier this week, moved down to third spot with seven points while Bielefeld have four points in the 13th place.