HARD WORK PAYING OFF
The away side have covered eight kilometres (five miles) more than their host this evening as a team.
There's four minutes of added time here in Dortmund.
The sixth Dortmund man booked tonight after his challenge on Latza.
HAKIMI FORCES A SAVE
Hummels' initial shot is blocked and runs loose across the edge of the Mainz box. Hakimi gathers and hits it on target, but it's straight at Müller for a simple save.
Despite still having Hazard, Haaland and Hakimi on the pitch in attack, Dortmund are finding no way through the Mainz defence.
LAST CHANCE SALOON
Schulz is on for Guerreiro and Dortmund are into last chance saloon here. Mainz looking good for a huge three points this evening.
Guerreiro and Latza booked for an off-the-ball incident.
BIG SAVE DENIES SZALAI
The substitute controls in the box and turns to shoot at goal, but Bürki makes a huge save down low to his right to keep the deficit at two.
Dortmund's top scorer and top assister has been sacrificed with Mateu Morey coming on.
AS THINGS STAND
Three points this evening will take Mainz six clear of Werder Bremen in the relegation play-off spot with two games to play, and the first of those being at home to Bremen on Saturday.
Barreiro and Szalai are on to run their hearts out for the final 15 minutes here.
HAKIMI SO CLOSE!
A great free-kick from the wing-back curls towards goal, but Müller is across to make a fantastic save and tip the ball over his own crossbar.
HUGE CHANCE FOR BOETIUS!
He has to score that and end the game. A cut back from Öztunali finds Boetius in front of the Dortmund goal with space to pick his spot, but he fires it wide past the near post.
PUSHING AND PUSHING
It's all Dortmund now with Mainz waiting on counter-attacks. Still 20 minutes to play here and one goal could change everything...
All too easy for Müller though, as Hakimi takes a low shot from the edge of the box. Dortmund still unable to create clear chances here. Wide play not working, Haaland unable to get involved through the middle. A credit to the Mainz defence.
BRANDT GOES CLOSE
The midfielder takes aim from range with Dortmund's first real shot of anger in this second half. It whisks wide of the mark across Müller's goal.
MATETA ON THE BREAK
The Frenchman is one-on-one with Hummels after Can's failed clearance and he goes for goal himself, but Hummels makes a good block. There were options there for Mateta if he wanted help.
Mainz have covered almost 6km (3.7 miles) more than Dortmund already in this game as a team. The away side working hard for their lead and not letting Dortmund have any sniff of getting back into this so far.
WHAT A RECORD
Since May 2013, Mainz have scored all 27 of their penalties in the Bundesliga - a current league record.
The home side take off Piszczek and bring on Schmelzer less than 10 minutes into the second half.
The Dortmund defender is shown a yellow card for a challenge on Burkardt.
MAINZ DESERVING OF THIS
The away side are not allowing Dortmund a second to breathe on the ball when the home side bring it into the Mainz half. So far, Dortmund have struggled to get past that pressing to create chances on goal.
MATETA SLOTS HOME!
Minutes after missing a good chance, Mateta makes no mistake with his spot-kick. He strolls up confidently and sends Bürki the wrong way with his penalty. Dortmund are down 0-2 at home and Mainz are deservedly in front.
GOAL!0 : 2
Latza is brought down in the box by Piszczek and Mainz have a penalty.
HOW WILL BVB RESPOND?
Just one attempt on goal since the 18th minute for the home side. They're struggling here early in the second half to get the ball in menacing positions again with Mainz pressing hard in their own half.
SECOND HALF UNDERWAY
No changes at the break for either side as we get things underway again here in Dortmund.
APPROACHING THE BREAK
It's the same story here with Dortmund on the ball but making mistakes throughout the pitch to stop themselves from getting forward with vengeance. Sancho missed a pass to Witsel in the Mainz box while Guerreiro has headed over. It's not going their way in this first half.
The Dortmund defender is the second man in black and yellow to receive a caution tody.
A FIRST FOR BURKARDT
In his 11th Bundesliga game, Jonathan Burkardt has scored his first Bundesliga goal. Not many better places to do it.
CAN SO CLOSE!
The ball drops in the Mainz box after a corner and bounces up kindly for Can in front of goal. He goes for it with his head but can't get power behind it and Müller clutches it and breathes a sigh of relief. Huge chance to bring the game level straight away.
MAINZ LEAD IN DORTMUND!
And what a goal it is. The away side push the ball wide with Mateta finding Baku out on the right. He curls a perfect cross to Burkardt at the near post and he glances the ball into the bottom corner beyond Bürki. Perfect attacking move from the away side.
GOAL!0 : 1
The Mainz left-back has the second yellow card of the game following Lukasz Piszczek after a late challenge on Hakimi.
Mainz break away with a rare counter-attack and it's Mateta who puts Burkardt in on goal. He has options around him to pass to but goes for goal himself. Hakimi flies in with a challenge, though, and it's enough to put him off with his loose touch sending the ball into Bürki's grateful arms. Can't let too many of those slip, Mainz.
LACK OF CUTTING-EDGE
Dortmund still enjoying the ball but have yet to have a shot on target in this first half.
MAINZ TRYING TO MAKE MOVES
A half-chance is all they're mustered so far with Latza sending a ball into the box which Kunde was unable to control at the back post. They've had little work with in the opening 20 minutes but are looking dangerous on the counter-attack with pace on the wings.
ALMOST FOR DORTMUND
Great interplay between Guerreiro and Hakimi puts the Portuguese wing-back into the box. He nutmegs a defender and tries to get a shot away, but his effort is snuffed out.
WITSEL SHOT BLOCKED
The Dortmund midfielder gets the first real chance of the game away. Guerreiro heads a cross down to him on the penalty spot, but the Mainz defence blocks his effort from close range.
It's been a good start from Dortmund, but not great. No clear-cut chances on goal despite their control of the ball and the Mainz defence is keeping Sancho, Haaland and Hazard in check so far.
Dortmund keeping the ball to themselves here in the opening minutes. Upwards of 80 percent of the ball and a Hazard shot over the bar. Both defences doing their jobs so far.
AWAY WE GO!
The ball is rolling in Dortmund for the visit of Mainz, let the fun begin!
READY TO ROCK!
We're just minutes away from kick-off here in Dortmund with some summer rain falling at the Signal Iduna Park.
RUN BOYS, RUN!
Both teams covered 78.6 miles in the corresponding fixture last season, which Dortmund won 2-1. That remains a club record for each.
No player has had a hand in more goals this term than Sancho, the young Englishman having laid on 16 alongside the 17 he has scored himself. Haaland has scored his 11 goals at a rate of one every 72 minutes since his winter transfer from Red Bull Salzburg. What will the duo produce today?
DORTMUND TEAM NEWS
Just one change for Dortmund after their 1-0 win at Düsseldorf last time out and it's the match-winner, Erling Haaland, who comes in for Manuel Akanji.
MAINZ TEAM NEWS
Six changes for Mainz here after their defeat the hands of Augsburg at the weekend. Mwene, Brosinski, Barreiro, Öztunali, Quaison and Awoniyi all drop out with Onisiwo, Boetius, Burkardt, Kunde, Baku and Martin all in for the trip to Dortmund.
DORTMUND STARTING XI!
Bürki - Piszczek (c), Can, Hummels - Hakimi, Brandt, Witsel, Guerreiro - Sancho, Haaland, Hazard
Hitz, Rente, Schulz, Balerdi, Bakir, Morey, Schmelzer, Duman, Raschl
MAINZ STARTING XI!
Müller - Baku, St. Juste, Niakhate, Martin - Kunde, Latza (c) - Burkardt, Boetius, Onisiwo - Mateta
Dahmen, Quaison, Öztunali, Ji, Brosinski, Mwene, Szalai, Barreiro, Hack