Speed check: The fastest player in the game after 90 minutes
Hertha fans bouncing
You would not quite believe that Hertha are 4-1 down here, given the way their sizeable following of fans are jumping up and down. Amazing support, given the circumstances.
Plenty of changes of personnel, Leverkusen looking ahead to European action on Thursday and Hertha giving a rest to key players - it appears both coaches know how this game is going to end.
Tah goes close
Tah has a chance to go into the referee's book for a positive reason, but he cannot quite add a fifth.
Ngankam and Tah try to swap shirts before the end of the match, and a yellow card is shown to them both.
Cherry on top
Adli with the pick of the bunch! He shows excellent pace and close control and hits a shot which takes a deflection off the shin of Rogel to leave Christensen no chance. Three-goal advantage restored.
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All scorers off
Perhaps one eye on the UEFA Europa League match with Ferencvaros on Thursday as Alonso replaces two of his goalscorers. The other - Frimpong - already left the field with injury.
Lukebakio has now converted five out of five penalties this season, and this one has given Hertha a lifeline. His 10th of the season, equalling his best ever season in the Bundesliga, from his Fortuna Düsseldorf days.
Penalty for Hertha
A lifeline for Hertha as Plattenhardt is brought down in the area, and a penalty is awarded.
Wirtz the creator
Wirtz is only playing his eighth game of the season and already he has provided four assists. Only Frimpong has set up more for Leverkusen so far this season.
xG may not have Leverkusen on three goals, but certainly their performance is worthy of such a comfortable lead.
Only half the story
Diaby seals it!
Surely that is it now. Just moments after hitting the crossbar, Diaby follows Hincapie's example and comes in diagonally from the left, threading his shot through Christensen's legs to make it three to Leverkusen.
Hincapie cuts in at pace from the left (sound familiar?), but his low shot is saved by Christensen's foot. No matter which side they come from, Leverkusen are so dangerous!
A change is as good as a rest
The first two changes are made by Sandro Schwarz - can Boetius and Jovetic provide the cutting edge Serdar and Niederlechner could not?
Christensen does well to deny a low Diaby strike, Leverkusen's first attempt of a second half which has so far seen Hertha take the game to the hosts.
Finally the last line of the Leverkusen defence has something to do, and he does it outstandingly well, tipping a low Lukebakio effort behind for a corner.
After a DIY job on the net, Leverkusen get us underway for the second half.
Hole in the net
The second half will start with a bit of a delay as a small hole has been spotted in one of the goals. Remember Kiessling's phantom goal against Hoffenheim? Better to stitch up the hole...
A very comfortable lead for Leverkusen at half-time. They have looked a threat whenever they have pushed forward, while Hertha have not managed a single shot on goal. Time for the two coaches to deliver what are likely to be very contrasting team talks in the dressing room.
Moussa Diaby Marc-Oliver Kempf
This is only the second time this season that Leverkusen have scored two goals before half-time. The first time was against Schalke, when a 2-0 interval lead became a 4-0 triumph on Xabi Alonso's debut as head coach.
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Attacking on all fronts
Leverkusen have scored twice when coming down the right wing, and they nearly got a third from the left. A grimace by Marco Richter says it all about how much Hertha are struggling here.
Hopeless for Hertha?
Hertha have not picked up a single point this season in games where they have fallen behind, and that has happened eight times.
Speed check: The fastest player in the game after 30 minutes
Frimpong throws in the towel
Unfortunately for Leverkusen, Frimpong has been forced to limp off the field with a muscular injury. He has scored one and made one, but Leverkusen fans will be concerned to see him leave the action so early.
5 of Frimpong's 7 Bundesliga goals have been set up by Diaby.
Hertha cannot find the target
Sucking it up
Frimpong on fire
For the first time in his career, Frimpong has scored and assisted goals in the same game.
Hertha do not learn the lesson of the first goal, so Leverkusen do it all over again. Diaby gets round the back on the right and cuts the ball back for Frimpong, whose low shot cannot quite be cleared off the line by Richter. Two almost identical goals for Leverkusen!
Azmoun almost at the double
The same combination which provided the opening goal link up again with Frimpong's pass turned towards goal by Azmoun, but Christensen tips it over instinctively!
Richter rifles one
A good response from Hertha, with Richter rifling in their first shot of the game, though he sends it wide of the far post. Hertha can no longer just sit back and soak up the pressure - they need to build some of their own.
Pressure pays off!
A great combination involving Diaby and Frimpong rips through the Hertha defence, and the latter pulls the ball back for Azmoun, whose slide-rule shot is cleared from just behind the line - at least that is what the referee's watch says, as he raises his arm for all to see the goal is given.
Putting the pressure on
Leverkusen goalkeeper Hradecky is making his 250th Bundesliga appearance. He has not touched the ball yet, but would be happy keeping things that way.
Leverkusen are looking to attack down the right, and given the pace of Frimpong, it is easy to see why. He races round the back, but his cut-back is turned behind for a corner.
Leverkusen on the ball
Just a minute on the clock and Leverkusen have forced the first corner of the game. Wirtz is over it, but Lukebakio clears it easily.
Away we go
It is Hertha who get the ball rolling at the BayArena, shooting from right to left in this first half.
Former Leverkusen CEO Rudi Völler is taking his place in the stands, as the teams emerge from the tunnel. Not long now!
Away day blues?
You have to go back to September 16 for Hertha's last point on the road, picked up in Mainz. Now would be a perfect time to remedy that record.
Hertha's players have already left the field after completing their warm-up. Leverkusen's players are still taking a few final shots before heading back to the changing room.
With Kossounou back, Andrich advances into the midfield having covered in the back three a week ago.
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Wirtz one of three changes
Hertha starting XI
Christensen – Rogel, Uremovic, Kempf - Richter, Tousart, Cigerci, Serdar, Plattenhardt (c) - Lukebakio, Niederlechner
Leverkusen starting XI
Hradecky (c) - Tapsoba, Tah, Kossounou - Frimpong, Andrich, Palacios Hincapie - Wirtz - Diaby, Azmoun
Hertha hope to climb
Hertha, on the other hand, can take a big step away from the relegation dog fight with a win. With Stuttgart, Hoffenheim and Bochum all losing, a win would put the Old Lady four points ahead of the drop zone.
European hopes fading
Leverkusen head into this game in 11th place, a full ten points outside the top six, and a potential return to the Champions League lies a further four points ahead. A win today is therefore quite necessary to revive any hopes of playing in Europe next season.
Early team news
Hosts Leverkusen have had good news in recent weeks, with Schick, Moussa Diaby and Florian Wirtz all back from injury, while Amine Adli, Piero Hincapie and Jonathan Tah return after suspension last weekend. As for Hertha, Marton Dardai and Marc-Oliver Kempf appeared to be injury doubts but both should be fit enough to start in defence.
Watch: Leverkusen's 1-1 draw with Freiburg
Watch: Hertha claimed big win last time out
Alonso: "We've conceded too many goals"
© Alexander Scheuber/Bundesliga/Bundesliga Collection via Getty Images
Schwarz: "We've got to drag the game our way"
© Boris Streubel/Bundesliga/Bundesliga Collection via Getty Images
Watch: The 2-2 draw between these sides on MD6
Leverkusen, meanwhile, have just one win in their last five Bundesliga matches and dropped to 11th after their 1-1 draw with Freiburg on Matchday 21. Coach Xabi Alonso needs things to turn around, and quickly, otherwise Die Werkself's season could end in the unfamiliar position of the Bundesliga's bottom half.
All or nothing Hertha
Hertha haven't drawn since a 2-2 share of the spoils with Frebiurg on Matchday 9. Since then, they've won four times and lost nine games so expect someone to take all three points on Sunday. Two of Hertha's four wins in that time have come across their last three games to get them moving in the right direction.