Leverkusen title hopes take hit in Union stalemate
Leverkusen could have cut the gap to league leaders Bayern Munich to three points with a victory. Bayern host Borussia Dortmund later on Saturday and can go eight points clear with five games remaining should they beat their 'Klassiker' rivals.
Despite welcoming back star midfielder Florian Wirtz from a foot injury, Xabi Alonso's side lacked fluency in attack, carving out few clear-cut opportunities.
Union had the ball in the net after 14 minutes when Andrej Ilic headed in a rebound after a save from Lukas Hradecky, but the Serbian was flagged for offside.
Wirtz came on after 57 minutes and despite giving his side an initial boost, was unable to break down Union's defence.
Granit Xhaka had a free-kick from the edge of the box in stoppage time but blasted his shot well over the bar.
"We're dropping too many points at home," Leverkusen captain Hradecky said, adding "mathematically there's a small chance (of defending the title), but the probability has decreased."
The draw continues a poor April for last season's unbeaten domestic double winners, who were eliminated from the German Cup semi-finals by third division Arminia Bielefeld.
The draw took Union to 34 points, 12 clear of the relegation spots with five games remaining.
Dangling close to the drop in February, just a year after facing Real Madrid in the Champions League, Union have turned things around.
The Berliners have taken 11 points from an unbeaten five-game run against Leverkusen, Bayern, Eintracht Frankfurt, Freiburg and Wolfsburg.
Borussia Moenchengladbach's hopes of returning to the Champions League took a hit with a 2-1 home loss to Freiburg.
Gladbach took the lead after 14 minutes when Freiburg captain Christian Guenter turned the ball into his own net. The visitors levelled two minutes later when Patrick Osterhage headed past Tiago Pereira Cardoso.
Freiburg snatched all three points when Johan Manzambi scored a 90th minute header, allowing the visitors to leapfrog their opponents into sixth.
Augsburg continued their strong 2025 with a 2-1 win at lowly Bochum, climbing past Dortmund into eighth. Augsburg have only lost one of their past 13 games.
Elsewhere, Hoffenheim took a step towards beating the drop with a 2-0 home win over Champions League hopefuls Mainz, with Andrej Kramaric scoring a brace.
The win sent Hoffenheim eight clear of the relegation spots, while Mainz -- who battled relegation a season ago -- missed a chance to climb to third on the table and stay fifth.
St Pauli also boosted their hopes of top-division football next season with a 2-1 win over fellow promoted side Holstein Kiel.