Champions Bayer Leverkusen have squandered a 2-0 lead for the third time in six Bundesliga games to end up with a 2-2 home draw against lowly Holstein Kiel on the second anniversary of coach Xabi Alonso's arrival.

There was also no luck for Borussia Dortmund as they crashed 2-1 at Union Berlin on Saturday, their second domestic defeat after midweek Champions League success.

Leverkusen were 2-0 up after eight minutes from Victor Boniface and Jonas Hofmann, but Max Gschwill, on the stroke of halftime, and Fiete Arp's 73rd-minute penalty gave the visitors a point that had appeared impossible early on.

Leverkusen had also wasted 2-0 leads on matchday one in a 3-2 win at Borussia Mönchengladbach, and a week later in a 3-2 home defeat against RB Leipzig.

Alonso started the Leverkusen job on October 5, 2022, in succession of Gerardo Seoane when they ranked second last, and led them to a maiden Bundesliga title in a landmark unbeaten last season, plus the German Cup title.

In Berlin, Kevin Vogt converted a penalty and Yorbe Vertessen doubled Union's lead shortly before halftime. Dortmund fought back from Julian Ryerson in the 62nd but could not find an equaliser.

Vogt scored for the first time in almost 10 years and after 275 games without success. Statisticians Opta said that was the longest scoring drought by an outfield player in league history.

But Dortmund's 10 points after six games represents their worst start in a decade, and coach Nuri Sahin said: "It is not easy to find the right words. We have to present ourselves in a different way, especially away from home."

Elsewhere, Jonas Wind scored a brace as Wolfsburg won 3-1 at Bochum who are now last after Kiel's point.

Freiburg prevailed 1-0 at Werder Bremen from Ritsu Doan and rose to third, while Jonathan Burkardt's brace helped Mainz win 3-0 at Jackson Irvine's St Pauli.

Sunday's games feature a table-topper between Eintracht Frankfurt and leaders Bayern Munich., Heidenheim v RB Leipzig and VfB Stuttgart v Hoffenheim.