FRANKFURT, Germany -- Mario Mandzukic scored both goals in Bayern Munich's 2-0 win over bottom-place Greuther Fuerth as the Bundesliga season resumed on Saturday after its one-month winter break.
Bayer Leverkusen stayed nine points behind league leader Bayern by beating Eintracht Frankfurt 3-1 in a match that was interrupted when Eintracht supporters launched fireworks onto the pitch.
Defending champion Borussia Dortmund, paced by its young stars Marco Reus and Mario Goetze, romped to a 5-0 win at Werder Bremen and stayed third, 12 points behind Bayern.
Wolfsburg gave new coach Dieter Hecking a winning start in a 2-0 victory over Stuttgart, Hoffenheim and Borussia Moenchengladbach played to 0-0, and Mainz and Freiburg also ended in a goalless stalemate.
Mandzukic brought his season total to 11 goals by scoring in each half in Munich, his first brace for Bayern. Bayern did just enough to gain a routine victory over an opponent trying to limit the damage.
The Croatia striker scored the first in the 26th minute, connecting with a volley that was fumbled by goalkeeper Wolfgang Hesl. The cross came from Thomas Mueller.
Mandzukic doubled the lead in the 61st, heading in a corner from Toni Kroos.
"It was important to start with a win," Mandzukic said.
Bayern stunned the league this week when it announced that former Barcelona coach Pep Guardiola would replace Jupp Heynckes at the start of the next season.
"I don't think that was a topic at all, the players didn't behave any differently," said Heynckes, whose contract runs out at the end of the season.
In Leverkusen, Germany coach Joachim Loew and German Football Federation (DFB) president Wolfgang Niersbach saw the match interrupted for about six minutes when Eintracht fans threw a couple of fireworks onto the pitch.
Referee Wolfgang Stark sent both teams to the changing room until the smoke cleared.
When they returned, Leverkusen overwhelmed Eintracht with two goals inside two minutes.
"We don't need such things in football. But we took advantage of the break because we had time to correct a few things that did not work well at the start," Leverkusen coach Sascha Lewandowski said.
Defender Sebastian Boenisch drove the ball inside the net in the 31st when Eintracht failed to clear a corner and the ball fell kindly in front of him. Less than two minutes later, Stefan Kiessling doubled the lead when he and Gonzalo Castro beat an offside trap to emerge alone in front of Frankfurt's goal.
Castro fed Kiessling, who easily notched his league-high 13th goal of the season. With Loew watching, Kiessling may have strengthened his case to be recalled to the national team.
Eintracht's problems in defence were exposed again when Kiessling fed Andre Schuerrle for Leverkusen's third goal in the 58th.
Alexander Meier cut the deficit in the 78th and Olivier Occean hit the post as Frankfurt stayed fourth despite the setback. Meier has 12 goals, one behind Kiessling.
Dortmund came out in devastating form against Bremen.
Reus scored from a free kick in the ninth minute, driving in over the wall. Goetze doubled the lead in the 19th with a slightly deflected shot from the edge of the area that bounced into the net from the underside of the crossbar.
Defender Felipe Santana made it 3-0 in the 48th, heading in a corner from Reus despite wearing a face mask to protect a broken nose.
The Polish duo of Robert Lewandowski and Jakub Blaszczykowski added late goals to complete the victory, both scoring from close range after counterattacks.
Nuri Sahin, who returned to Dortmund this month after spending 1 1/2 years in Real Madrid and Liverpool, came off the bench late in the game.
Wolfsburg's win was engineered by midfielder Diego, who scored the first goal in the 51st, beating Stuttgart goalkeeper Sven Ulreich from the edge of the area.
Alexander Madlung secured the win in the 78th by heading in a free kick from Diego.
Hoffenheim failed to win under new coach Marco Kurz and remains stuck in 16th place.
In Mainz, the home team finished with 10 men after Shawn Parker was sent off late in the match.