BERLIN (AP) -- Borussia Dortmund won 2-0 at Freiburg to get its Bundesliga title defense back on track in difficult conditions on Saturday.
Heavy snowfall hampered both teams in a hard-fought game.
"In the old days we'd want to go out in weather like this to play football but we weren't allowed because the mothers didn't want to wash the gear. Nowadays we have to go out but we don't want to,'' Dortmund coach Juergen Klopp said.
Neven Subotic scored in the 54th minute and Mario Goetze made the game safe for Dortmund with seven minutes remaining.
"To win 2-0 here in such conditions is extraordinarily good,'' said Klopp, whose side beat Real Madrid in the Champions League three days earlier.
Jefferson Farfan's 77th-minute strike was enough for Schalke to complete a perfect week with a 1-0 win at home over Nuremberg. Schalke won the Ruhr derby against Dortmund last weekend and then 2-0 at Arsenal in the Champions League midweek.
"Today falls under the category of dirty hard-work win,'' said Schalke captain Benedikt Hoewedes. "It wasn't a great game.''
Wolfsburg beat Fortuna Duesseldorf 4-1 away to end its seven-game run without a win in interim coach Lorenz-Guenther Koestner's first game in charge.
"The players were obligated (to win) because the coach was gone,'' said Koestner, referring to Felix Magath's departure on Thursday. "We scored at the right times and the team never stopped fighting.''
Elsewhere, Mainz beat Hoffenheim 3-0 thanks to an Adam Szalai hat trick, and Greuther Fuerth drew 1-1 at home with Werder Bremen.
Dortmund's first away win of the season leaves it nine points behind Bayern Munich, which plays its game in hand against Bayer Leverkusen on Sunday.
Freiburg came closest to scoring in a scrappy first half, when Subotic made a crucial clearance to concede a corner that caused panic in the Dortmund defense in the 15th.
Daniel Caligiuri was twice blocked, and then Marcel Schmelzer got the slightest touch to the ball with his studs to push Erik Jendrisek's effort onto the post.
Subotic made the breakthrough with a header from a dangerous Marco Reus free kick, and the game was settled when Robert Lewandowski set up Goetze for a low shot past Oliver Baumann.
"It's nice that we can angry about losing after such a game,'' said Freiburg coach Christian Streich. "We're happy that we can compete at this level.''
Dutch striker Bas Dost ended Wolfsburg's longest streak in the Bundesliga without a goal (457 minutes), when he opened the scoring five minutes into the second half at Duesseldorf with a tap-in from Ivica Olic's cross.
Diego crossed for Olic to make it 2-0 three minutes later, and Dost claimed his second goal in the 64th.
Jens Langeneke gave the home fans some hope in the 71st with a penalty Olic conceded by fouling Oliver Fink, but it didn't last long.
Fink was sent off six minutes later for bringing down Diego in the penalty area, and the Brazilian duly converted the spot kick.
"It's a new start for all of us,'' said Diego. "I'm very proud of the team.''
Hoffenheim goalkeeper Tim Wiese endured another afternoon to forget in Mainz.
Hungary striker Szalai opening the scoring in the 21st, adding another seconds after the restart, and claiming his seventh of the season in the 64th.
"It's a special day for me. I never scored three goals (in one game) before,'' Szalai said.
Hoffenheim has yet to win with Wiese in the side. The former Germany goalkeeper has conceded 21 goals in six competitive games since moving from Werder Bremen.
"I have no idea why it's not working,'' Wiese said.
Hoffenheim has the worst defense in the league and defender Marvin Compper didn't pull any punches: "It makes me sick how we're conceding goals.''
Brazilian striker Edu scored Fuerth's first goal at home in the Bundesliga in the eighth minute, but Bremen deservedly equalized one minute before the break through Nils Peterson.
"We're very, very happy that we won't have to hear next week that we can't earn points at home and that none of the strikers can score,'' said Fuerth coach Mike Bueskens, whose side is now bottom.
On Sunday, Eintracht Frankfurt visits Stuttgart and Hannover hosts Borussia Moenchengladbach.
Hamburger SV got the ninth round underway on Friday with a 2-0 win at Augsburg.