The side-effect of this crucial victory for Borussia Dortmund is the crowning of Bayern Munich as Bundesliga champions by default. The fact that Bayern were celebrating 478 kilometers away won't dampen Dortmund's spirits though – Champions League football is now within their grasp. Eintracht Frankfurt can still turn the tide in this absorbing race for the top four, but the momentum is with Dortmund, especially after this rousing victory. Five straight league wins plus another in the Cup is allowing them to banish memories of a turbulent season at the time it matters most.  Mahmoud Dahoud was Dortmund's best player and continues to thrive since coach Edin Terzic handed him a run of games in the team only because of an injury to Thomas Delaney. Dahoud's skill and ingenuity has never been questioned, but his consistency and application has. It is no coincidence that Dortmund's run has coincided with purple patch, and he was spellbinding again here. But it was Jadon Sancho's cool head in front of goal that was the decisive factor for Dortmund. In the absence of Erling Haaland, whose injury continues to make him a doubt for the Cup final, Sancho offered a timely reminder that Dortmund possess more than one world class attacker. While the result extinguished Leipzig’s faint title ambitions, this could prove the precursor to a sepulchral week for Julian Nagelsmann’s side. Dortmund will now go to Berlin with a mental edge that shouldn’t be underestimated and fresh belief that for all of Leipzig's quality, Dortmund pack a greater punch. "We did well in parts, very badly in others," Nagelsmann said. "In the second half, we were the better team. Three goals against are too many. That's why we lost. Everything will have to be right on Thursday." Nagelsmann will spend the next days trying to crack the code, but it's a lock he's been trying to pick for a while. He's only got the better of Dortmund once in 11 attempts — four with RB Leipzig and seven with Hoffenheim — and he tends to struggle against teams with freewheeling and unpredictable attacks. Thursday's Cup final will determine whether this season has been a success or a failure for both clubs. Nagelsmann is determined to arrive in Munich as a winner, having failed to win a trophy so far in his career. And for Dortmund, a fourth placed finish is the bare minimum they expect. There is a lot riding on the game in Berlin, but Dortmund will go there with a blueprint of how to beat Leipzig in their top pocket. Nagelsmann needs to show he has the answers.