Bayer Leverkusen dropped eight points behind league leaders Bayern Munich with a scoreless draw at Wolfsburg on Saturday.

Bayern's 3-0 win over Werder Bremen on Friday, their seventh straight league win, upped the ante on Xabi Alonso's defending champions, who host the leaders next Saturday.

Alonso named a weakened starting lineup with Florian Wirtz, Patrik Schick and Jeremie Frimpong all left on the bench after playing 120 minutes in Tuesday's extra-time German Cup win over Cologne.

Without their star trio, Leverkusen lacked fluency. Nordi Mukiele had a golden chance to put the visitors in front after 22 minutes, but headed over the bar while unmarked from point-blank range.

Wirtz and Frimpong came on after 60 minutes but the visitors had few chances despite dominating possession.

Wirtz went down in the box with 13 minutes remaining after some light contact prompting a VAR check, but the referee waved it away.

The 21-year-old had a chance to snatch his side the win in stoppage time, but he blasted just wide.

Leverkusen have dropped four points in their past three league games, leaving their bid to defend their debut title on life support.

Conceding the eight-point gap to the league leaders was "much bigger than it should be", Leverkusen captain Lukas Hradecky said "this weekend hasn't made it easier for us to achieve our dream.

"With the way Bayern are at the moment, we can't have anything but a home win," Hradecky said of Bayern's visit next week.

His manager struck a different tone, saying he was "not overly worried" about the widening gap.

"We'll have a bit of a break and start preparing on Tuesday. We're playing Bayern at home -- top game, top atmosphere -- we're still focused on us, and what we can achieve."

- Dortmund lose on Kovac debut -

Stuttgart won 2-1 at Borussia Dortmund to go fourth, spoiling Niko Kovac's debut in the home dugout.

Stuttgart's Deniz Undav and Dortmund's Karim Adeyemi had chances in the opening half before centre-back Waldemar Anton, who left Stuttgart for the Westfalenstadion in the summer,  put the visitors in front in the 50th minute.

Stuttgart's Jeff Chabot put the visitors two goals up on the 61st-minute mark, knocking in a superb volley for his first Bundesliga goal.

Julian Brandt scored late but it was not enough, as Stuttgart beat Dortmund for a fifth straight time.

Kovac, named coach this week after Nuri Sahin was fired in January, has his work cut out for him, with Dortmund mired in 11th spot.

The coach praised his charges, saying "the boys gave it their all -- we shouldn't have left the field as losers," adding some poor decision-making had "deprived us of the fruits of our labour."

Freiburg climbed to sixth with a hard-fought 1-0 win over Heidenheim, with a first-half header from Vincenzo Grifo the difference.

Italy winger Grifo, known for his set-piece prowess, headed in a lovely Ritsu Doan cross to put his side on track for a third European qualification in four seasons.

Union Berlin chalked up a statement victory in their battle to avoid the drop, winning 4-0 at struggling Hoffenheim.

Union, who hosted Real Madrid in the Champions League last season but started Saturday's game in 14th, won thanks to a brace from Benedict Hollerbach and goals from Marin Ljubicic and Andrej Ilic.

The win took Union 10 points clear of Heidenheim, who sit in the relegation playoff spot.

Also on Saturday, Mainz and Augsburg played out a scoreless draw.

In the day's final match, Borussia Moenchengladbach host third-placed Eintracht Frankfurt.

dwi/pb/nr