Full time! Union 0-0 Leverkusen
Union stay third with four games to go. They made life very difficult for Leverkusen, who are now unbeaten in 14 competitive matches but eight points outside the top four following wins for Freiburg and Leipzig.
Three minutes to find a winner...
Roussillon pulls up injured. He's put in a really energetic shift, shutting down Diaby among others. Gießelmann is on for the remainder.
Union go on the offensive after a Leverkusen attack breaks down. Becker tries to feed Schäfer on the edge of the box, but the Hungarian is nudged off the ball by Tapsoba as he goes to shoot.
Rönnow made to work!
Bakker rises to meet Frimpong's cross, heading the ball towards the bottom corner. It's a fairly routine diving save for Rönnow, though.
No way through
Heading for a draw
Fischer shows his hand - can Union nick a late win? Neither goalkeeper has been seriously tested yet...
Andrich has a goal-bound shot from the edge of the area blocked. Kossounou is then booked for pulling back Roussillon as Union tried to break free.
Schäfer makes his return following injury. It's his first appearance since the Berlin derby win over Hertha at the back end of January.
Leite is cautioned after hauling down Adli in an attempt to stop a Leverkusen counter. That's his fifth booking of the campaign - he'll now miss Union's trip to Augsburg next weekend.
Hlozek and Diaby have ploughed a lonely furrow. Azmoun - Bayer's joint top scorer in 2023 with four Bundesliga goals - and Adli are their replacements.
Bakker races back to stop Laidouni applying a close-range finish to Roussillon's probing low cross. Union have gone up a gear.
Wide from Becker!
Roussillon gets to the byline and cuts a ball back to Becker, who shifts inside and curls an effort narrowly wide of the far post. The Union forward has been his team's best player so far - can he cap his performance with a goal?
Live table talk
Elsewhere in the Euro race, Leipzig and Freiburg lead Hoffenheim and Cologne respectively. As things stand, Union are still third, albeit ahead of Freiburg on goal difference. Leipzig are two points back in fifth, while Leverkusen have six points to make up on the top five.
Union winning the individual battles
Aissa Laidouni Adam Hložek
Sheraldo Becker Odilon Kossounou
Jordan Edmond Tapsoba
High and wide
Laidouni swings a boot at Hincapie's headed clearance, but can't keep his 18-yard strike down. The Tunisian appears to be playing closer to Union's front two compared to the first half.
Union are straight on the attack as Haberer tumbles in the box under pressure from Tapsoba, but there's nothing in that. Both teams are unchanged...
Half time: Union 0-0 Leverkusen
Tah heads a Wirtz corner comfortably wide as a keenly contested first half comes to an end. It's been open and easy on the eye - but with defences very much on top.
Wirtz dinks a wonderfully disguised pass into the Union box for Frimpong, but he slips again and the chance is gone. Is this the work of the Union groundsmen?
13 times under pressure
Frimpong's caught out of position as Haberer combines well with Becker in the Bayer box. He returns a cross-shot with interest, but Kossounou slides in to stop the ball finding Becker.
Union still slight favourites to get the win
Juranovic in the way
Diaby bends an inviting cross towards the far post. Bakker's ready and waiting, but Juranovic beats him to it.
Union staying touch tight
Great feet from the twinkle-toed Wirtz to wriggle clear of his marker on the edge of the Union area. He tries to feed Hlozek to his right, but Union get it clear. The Leverkusen forwards are finding very little joy in the final third.
Leverkusen's flying Dutchman loses his footing as he goes to whip in a cross, rolling his left ankle in the process. It looks painful, but he's going to try and run it off.
High on energy in the capital...
Leverkusen can't live with Becker's pace. He pops up on the right this time to hook a cross into the area that Andrich heads clear in front of Haberer, who had snuck in unmarked at the far post.
Chance not taken!
The black shirts are in retreat as Becker runs at the Bayer defence. He has Jordan to his right, but Hincapie cuts out the Union forward's attempted pass into the six-yard box. He's furious with himself for not pulling that off. The net might have bulged, if he had.
Leverkusen seem to be playing with more of a back three, with Tapsoba stationed in defensive midfield rather than in the centre of a four-man defence.
It's Leverkusen's turn to pick the Union pockets. Andrich is the instigator, the ball goes through Wirtz, who feeds the run of Diaby to his left. The Frenchman's running at full pelt, though, and can't keep his shot from just inside the area down.
Trademark Union efficiency
Jordan stays down after landing awkwardly going to meet that cross. After some TLC from the physios, the American appears OK to continue.
Union continue to ask all the questions as Becker arrows a cross into the six-yard box. Jordan makes his move, but Kossounou makes another vital intervention. The hosts keep the ball alive after the ensuing corner is initially cleared. A ball comes in from Haberer with Jordan first to it and heading wide.
The Surinamese forward receives the ball on the edge of the Bayer box. He twists and turns before getting off a shot that Kossounou does really well to block on the stretch.
Union win back possession in the Leverkusen half. There's not much on for Becker, so he opts to have a crack from range. Union's nine-goal top scorer hits it well, but Hradecky is able to bat the ball into the ground and gather at the second attempt.
Just to emphasise the size of the task facng Leverkusen: Union have nine wins and five draws in front of their own fans in this season's Bundesliga, and only lost to Bayern and Dortmund here last term.
Under way in Berlin!
Superb atmosphere, but will the Union fans be celebrating come the full-time whistle?
Are Union in the title race?
Well, they're certainly not out of it! Dortmund's draw with Bochum on Friday means Union will climb to within a point of second-placed Bayern, who host Hertha tomorrow, with a win today. They'd also just be three behind current leaders BVB, with four rounds of fixtures to go.
Watch: Star power
More on those teams
One enforced changed for Union, with American striker Jordan replacing the suspended Kevin Behrens. As for Leverkusen, defender Edmond Tapsoba and teenaged playmaker Florian Wirtz return to the side. Kerem Demirbay and Amine Adli drop to the bench.
Union starting line-up
Ronnow - Doekhi, Knoche, Leite - Juranovic, Laidouni, Khedira (c), Haberer, Roussillon - Becker, Jordan
Grill, Jaeckel, Gießelmann, Trimmel, Thorsby, Schäfer, Michel, Pantovic, Leweling
Leverkusen starting line-up
Hradecky (c) - Kossounou, Tah, Tapsoba, Hincapie - Andrich - Frimpong, Wirtz, Bakker - Diaby, Hlozek
Pentz, Sinkgraven, Fosu-Mensah, Demirbay, Mbamba, Azhil, Azmoun, Adli, Bellarabi
Coach view: Union
Coach view: Leverkusen
Xabi Alonso: "Union Berlin are third in the table; they deserve to be there and are a really top opponent. We expect a tough game, but of course we hope for a positive result. We are totally focused. There are still five games to go before the end of this Bundesliga season. May is the most important phase."
Watch: Leverkusen 5-0 Union - previous meeting
Watch: Gladbach 0-1 Union - highlights
Watch: Leverkusen 2-0 Leipzig - highlights
Don't mention the Champions League!
Union staff continue to avoid the top-four question, but for how long? The Berlin club cemented third place with victory over Gladbach last time out, leaving their UEFA Champions League prospects firmly in their own hands. Whatever happens this weekend, they cannot drop lower than fourth.
Leverkusen the form team
Propelled by an eight-match unbeaten run, Xabi Alonso's Leverkusen have carved out a two-point buffer in sixth and are just six points outside the top four with five rounds of fixtures remaining. When the former midfield great took over from Gerardo Seoane at the start of October, Die Werkself were second bottom...