Mainz started the match highly motivated against the Champions League finalists, knowing a win would lift them out of the relegation zone on Saturday night.
The hosts put Dortmund on the backfoot as Nadeem Amiri rattled the crossbar in the seventh minute, moments later Silvan Widmer's header hit the left post.
Mainz broke the deadlock just 12 minutes from time when Leandro Barreiro exchanged a one-two with Vidmar before drilling the ball past goalkeeper Alexander Meyer into the bottom left corner.
Meyer remained in trouble and helped Mainz double the lead as he fired an offside free kick into the path of Lee Jae-sung, who made a mistake to send the ball into the roof of the net in the 19th minute.
Mainz continued to press and trebled their lead after just four minutes when Lee benefited from good build-up work and an assist from Barreiro.Mainz should have taken the lead, but Lee and Barreiro's accuracy in front of goal was lacking. According to Xinhua report, Dortmund did not pose any threat to the host's well-positioned wall.
In the 52nd minute, Edin Terzic's men thought they had reduced the gap through Youssoufa Moukoko, but the German international's goal was ruled offside by VAR.
With the result, Mainz extended their unbeaten streak to eight matches, with Dortmund remaining in 5th.
“One team fought to win, and the other just wanted to play football.We always came late in all the duels. This difference has arisen today. This is a tough defeat that hurts us very much. But this is more than fair. “It's a very sad evening for us,” said Dortmund coach Terzic.In other matches on Saturday, relegation-threatened Cologne boosted their survival hopes with a 3-0 win over Union Berlin.
Substitute Benjamin Cesco converted a penalty to give fourth-placed Leipzig a 1-1 draw with Werder Bremen.
Westfal Freiburg shared the spoils with Heidenheim after a 1-1 draw, Eintracht Frankfurt beat Borussia Mönchengladbach 1-1 to maintain their chances of a top-six finish.
On Friday, Stuttgart beat Augsburg 1-0 thanks to Serhou Guirassy's only goal, helping the Swabians overtake Bayern Munich in the standings.
The hosts put Dortmund on the backfoot as Nadeem Amiri rattled the crossbar in the seventh minute, moments later Silvan Widmer's header hit the left post.
Mainz broke the deadlock just 12 minutes from time when Leandro Barreiro exchanged a one-two with Vidmar before drilling the ball past goalkeeper Alexander Meyer into the bottom left corner.
Meyer remained in trouble and helped Mainz double the lead as he fired an offside free kick into the path of Lee Jae-sung, who made a mistake to send the ball into the roof of the net in the 19th minute.
Mainz continued to press and trebled their lead after just four minutes when Lee benefited from good build-up work and an assist from Barreiro.Mainz should have taken the lead, but Lee and Barreiro's accuracy in front of goal was lacking. According to Xinhua report, Dortmund did not pose any threat to the host's well-positioned wall.
In the 52nd minute, Edin Terzic's men thought they had reduced the gap through Youssoufa Moukoko, but the German international's goal was ruled offside by VAR.
With the result, Mainz extended their unbeaten streak to eight matches, with Dortmund remaining in 5th.
“One team fought to win, and the other just wanted to play football.We always came late in all the duels. This difference has arisen today. This is a tough defeat that hurts us very much. But this is more than fair. “It's a very sad evening for us,” said Dortmund coach Terzic.In other matches on Saturday, relegation-threatened Cologne boosted their survival hopes with a 3-0 win over Union Berlin.
Substitute Benjamin Cesco converted a penalty to give fourth-placed Leipzig a 1-1 draw with Werder Bremen.
Westfal Freiburg shared the spoils with Heidenheim after a 1-1 draw, Eintracht Frankfurt beat Borussia Mönchengladbach 1-1 to maintain their chances of a top-six finish.
On Friday, Stuttgart beat Augsburg 1-0 thanks to Serhou Guirassy's only goal, helping the Swabians overtake Bayern Munich in the standings.
