The two have met but the match ended in a 1-1 draw, the opportunity to stop Leverkusen is impossible because Dortmund is fifth in the standings now. Leverkusen was even able to draw when facing Bayern Munich, which is much stronger than Dortmund. This season the Bundesliga is a little different from previous seasons because the dominance of Bayern Munich and Dortmund will be broken again if Leverkusen manages to appear solid until the season ends.
Xabi Alonso just needs to do something so that his team can be much more solid and consistent and maybe he needs to pay attention to player fatigue when playing. If this can be handled well then Leverkusen has a real chance of becoming the team that will lift the Bundesliga trophy this season.
This season's Bundesliga has indeed given a new color with the presence of Bayern Leverkusen, who have appeared very impressive since the start of the season until now, and have not even been defeated. And it is true that Leverkusen did not lose against Dortmund and Bayer Munich. I don't think it's a coincidence that Xabi Alanso's squad this season is really strong and full of confidence, I don't think anything can stop them from winning the Bundeliga title this season.
Even though later in the second half of the season they meet each other again, I'm sure they won't be able to beat Bayern Leverkusen. I predict that this season Bayern Leverkusen can win the Bundesliga and Europa League titles. Because he deserves it, Xabi Alonso has done an extraordinary job because he has succeeded in developing the talents of his players into one unit, especially since Bayer Leverkusen has many world-class players such as Wirtz, Grimaldo, Frimpong, Boniface, Hoffman and Tah.