85' SUB: Dortmund make a change, too, as Witsel belatedly joins the fray, replacing Dahoud.
85' SUB: A defensive change for Bayern. Boateng bows out for Hernandez.
83' POST! Lewandowski! So close! That could have been the game! The striker shapes to shoot and sees a low curler deflect off Hummels and against the post. Gnabry hacks over the top on the rebound.
82' Burki looks far less convincing than Neuer as he comes for a deep Davies cross, getting there ahead of Lewandowski but only just gathering at the second attempt.
79' Dortmund are getting on top again now. Can lines up a shot but instead dummies once more, playing in Hakimi. Alaba deals with a low cross, though.
78' OFFSIDE! The flag spares Hazard's blushes! Dortmund move the ball right to Can, who dummies and then crosses low to Hazard, who is ahead of the defence. Incredibly, from the centre of goal, he misses the target and then goes down apparently claiming he was fouled. The winger is offside, however.
76' Not quite from Muller! Davies leads a counter on the left and feeds Muller, but he cannot find the overlapping Gnabry on the turn. The winger checks his run and keeps the ball in, allowing Bayern to build again. But Perisic blasts over from 25 yards.
75' Guerreiro takes the free-kick and catches it well, but the effort is straight at Neuer. The goalkeeper has made a couple of those attempts look very straightforward today.
74' YELLOW: Davies cannot believe it as he is penalised and carded for a foul on the edge of the area. Kimmich halts Hakimi with a good tackle, but Reyna beats Davies to the loose ball.
73' SUB: Bayern make their first change, with ex-Dortmund winger Perisic on for Coman.
72' SUB: Reyna is on for Dortmund, and there might be concern for Haaland, who makes way. The striker is moving awkwardly after stretching for a Sancho cross.
71' What a ball from Sancho! His best moment of the match so far sees the winger tear up the left and send a curling cross towards the far post and Haaland. It bounces agonisingly wide, though, having appeared to have taken a nick off Boateng. No corner.
69' Dortmund have had slightly more possession in the second half - 53 per cent - but have only mustered three fairly feeble shots.
67' YELLOW: Now Dahoud is carded, having slightly overrun the ball and left a foot in on Kimmich.
66' YELLOW: Muller is really late into a tackle with Akanji and goes into the book.
64' Lovely footwork from Guerreiro opens up the pitch and allows Dortmund to attack, but his team-mates are again too slow in the final third. They end up going backwards.
63' Dahoud's deflected pass wins a corner, which Dortmund take short from the right. It finally finds Guerreiro on the left, and a clipped cross is missed by two jumping Bayern players. Kimmich controls under little pressure, however, and clears.
61' Dortmund are dallying in possession, allowing Bayern to get men back in defence and then launch counters. They need to step up a gear again.
59' Bayern clear the corner, too. That is a big let off. Dortmund need to take these chances.
59' BLOCK! Oh, this is a huge chance! Hazard collects on the left-hand side of the area and squares to Haaland, who controls as Boateng slips. The striker has a clear shot at goal but shoots against the prone defender. The ball spins behind, having appeared to catch Boateng's arm, but there is no penalty and no appeal.
57' Dortmund are growing really frustrated. Haaland is struggling to link up with his team-mates, this time dropping short as the pass goes long in behind. Poor.
55' Sancho is struggling a little. Even as he beats Muller with a nutmeg, the pass to Hazard is misplaced. Dortmund need their talisman to get up to speed quick.
54' SAVE! BLOCK! Crucial stop from Burki! And then Hummels to the rescue! Dortmund are hanging on! Goretzka shoots low and Burki parries, only for Gnabry to gather the ball and dart into the area. A square pass appears to give Lewandowski an open goal, but Hummels intervenes brilliantly.
46' Bayern quickly win a corner with a move down the left, but Dortmund clear the set-piece. They fail to counter effectively, however.
46' KICK-OFF: Bayern get us started again. They are 45 minutes away from a seven-point lead over Dortmund at the summit.
46' SUB: The second switch sees Can replace Delaney in the middle of midfield.
46' SUB: A double Dortmund change! And Sancho is on. It is Brandt who makes way for the winger, slightly surprisingly.
43' GOOAAALLLL!!! INCREDIBLE! Kimmich! 1-0 Bayern! The visitors have Dortmund on the back foot, and Kimmich picks up possession when Davies' pass is cut out. He moves forward and, spotting Burki off his line, lifts a delicious chip over the goalkeeper into the top-left corner. Burki gets a hand to the ball but cannot turn it over the crossbar.
41' Frustration for Bayern. They win a corner on the right that passes straight through the area, although excellent work from Gnabry wins the ball back twice. He is then felled, but Goretzka picks up the ball and keeps running. A cross loops behind, but the referee deems there to be no deflection.
40' SAVE! No risks from Burki! He punches clear as Goretzka thunders in a 20-yard shot following a poor Hakimi header.
39' So good from Davies! And yet Hummels is there to cover. The Bayern man beats three or four players to breach the box, leaving only Hummels in his path. The experienced defender nudges Davies to the floor, though, and wins a goal-kick.
38' Hakimi and Davies are taking it in turns to run at one another. This is an engrossing battle, with neither able to steal a march at this stage.
37' Good tackle from Kimmich this time! Dortmund are moving the ball really smartly in the Bayern half, playing around Davies on this occasion. Kimmich halts Hazard as he cuts in from the left, however.
35' So disappointing from Brandt! Dortmund have the ball straight back down the other end, and Dahoud picks out a lovely pass to Brandt in space on the right when Bayern crowd the other side of the area. A first time cross is so, so poor, though, and drifts behind.
34' Whatever Davies can do, so too can Piszczek right now! Another last-ditch tackle denies Muller in the area as he stretches to shoot.
32' Outstanding from Davies! Haaland races away from Alaba, but the left-back appears capable of recovering from anywhere on the pitch with his pace. One scruffy touch from the striker lets Davies in.
31' Again Dortmund cannot muster an effort of note when they are well positioned! Alaba hacks a cross behind to concede a corner, and BVB work the set-piece to Hakimi for a centre from deep. He finds Hummels, but the former Bayern man chooses to nod down to Brandt rather than go for goal uncontested at the back post. Brandt cannot control.
30' Haaland really should do better! He wins the ball just as Bayern look comfortable, feeding Hazard and getting into space for the return. The pass arrives, yet Haaland's shot on the left lacks power and is deflected away.
28' Dortmund have Bayern penned in with four consecutive crosses making the visiting defenders work. Alaba beats Haaland to the crucial final header, though, and Davies can clear.
26' Dortmund go straight down the other end and really should forge an opportunity, with Brandt first failing to find an angle and then seeing the same fate befall Dahoud on the left corner of the area.
25' Magnificent defending again from Piszczek! He lunges in to steal the ball off Lewandowski's toe as his former team-mate looks to be winding up a 25-yard shot.
24' Bayern win a corner as the ball deflects behind off Guerreiro. The wing-back is then the man carrying the ball clear as Dortmund deal well with the set-piece, yet BVB fail to make the most of their superior numbers in attack.
23' SAVE! Burki keeps Coman out! Bayern move the ball with such speed after Davies takes down a long ball on the left. Muller feeds Coman, and the winger shoots hard but straight at the goalkeeper. An awkward parry just evades Muller.
19' OFF THE LINE! What a clearance! Bayern almost have the lead! Coman's low cross from the right finds Gnabry completely unmarked in the centre. His shot beats Burki, but Piszczek recovers to clear and get the ball away from the lurking Lewandowski.
18' Back come Bayern after Hazard gives the ball away. Muller crosses low to the near post as Lewandowski moves towards the far, allowing Hummels to sweep clear.
17' A slack touch from Davies gives the ball to Hazard, who gets beyond Alaba. Davies is quick enough to get back and close down the route to goal, however, and Dortmund have to build again.
16' Bayern have just wrestled back some control. The pattern of play is now perhaps more like many would have predicted it to be. Dortmund are playing on the counter.
14' Dortmund miss a big chance to counter! Delaney is the man furthest forward in attack, yet he has Haaland running right and Dahoud moving left. The pass to the latter is too heavy, though.
13' YELLOW: The first booking goes to Hummels, who takes down Coman.
9' OFFSIDE! Dortmund have the ball in the net, but it won't count. A wonderful move creates space for Hazard down the right, with Davies dragged out of position, and he picks out Haaland. A low shot is blocked by Alaba, as is Hakimi's follow-up, but the ball spins back to Hazard. Hazard is offside, however, as he centres for Hakimi to head in.
8' Bayern had some issues with set-pieces against Eintracht Frankfurt on Saturday, but the first corner is diverted clear at the near post.
7' Davies shows his incredible athleticism to get back and tackle Haaland on the right, although he concedes a corner.
6' Dortmund have had 64 per cent of possession in the first six minutes. They are well on top already.
5' Lewandowski is predictably involved as Bayern come forward for the first time. The striker bursts into the area but is stopped not once but twice by Akanji, who was excellent at Wolfsburg on Saturday.
4' Neuer holds on! A glorious switch gets Guerreiro in behind on the left, and he cuts a pass back into Brandt's path. Haaland is in the centre, but Brandt goes for an ambitious 20-yard curler and picks out only the goalkeeper.
3' This is a really confident start from Dortmund. They are pinging the passes around, with Bayern struggling to get a touch in the opening minutes.
2' There is a particularly tasty tussle in store on Dortmund's right flank, even without Sancho, as Hakimi goes up against Davies. The BVB man gets the better of the first battle, with Alaba required to intervene.
1' OFF THE LINE! What a start! Dortmund are straight on the attack! Neuer races from his goal to beat Hazard to a ball in behind, but Haaland pounces. From the edge of the area, the young striker nutmegs Neuer with pinpoint accuracy, only to find his slowing strike stopped on the line by Boateng.
1' KICK-OFF: We are under way in Dortmund!