Saturday's cup final was the sixth time Tuchel has faced off against Guardiola and each time he's failed to win. The Dortmund coach will have to figure out how to beat Bayern if he wants a Bundesliga title.
The German Cup final concluded with joyful tears from Pep Guardiola and jubilation from his Bayern Munich players as they ended the Spanish coach's final season in Munich with a domestic double.
Down on the pitch, watching the Bundesliga champions celebrating in the stands, was the chastened figure of Thomas Tuchel, perhaps going back over the last 120 minutes of football in his head and wondering what might have been.
"I am angry," the Borussia Dortmund coach told German television at full time. "I should have picked different penalty takers. My mistake."
Tuchel was undoubtedly proud of his side for pushing the German champions through 90 minutes, extra time and then to penalties before they fell in the cruelest possible manner in a shootout.
But once again, Guardiola had bested the coach from the small Bavarian town of Krumbach who made his name at lowly Mainz before joining powerhouses Dortmund.
Saturday's result was the sixth time that Tuchel and Guardiola have faced one another and the sixth time that Tuchel has failed to beat the coach he is happy to call the best in the world.
Tuchel has enjoyed an impressive debut season at Dortmund but has come up short when tackling the club’s biggest domestic rivals: After three attempts since joining his new club the coach still hasn't beaten Bayern.
Dortmund fans will undoubtedly be grateful for the record-breaking tally Tuchel's side amassed to finish second in the Bundesliga and the manner in which their club challenged Bayern in the Cup final.
Yet if the Westfalenstadion side are to realize their ambition of winning domestic silverware Tuchel and his squad need to find something extra.
Dortmund have proven themselves as the second best team in the Bundesliga but it was their performances against Bayern in their two league encounters which ultimately scuppered any unexpected title challenge.
Their 5-1 defeat at the Allianz Arena in October wasn't far off what many expected when Guardiola's polished side came up against Tuchel's fledgling team.
In the reverse fixture in March Dortmund played out a careful 0-0 draw rather than push on and risk the win.
That night Tuchel made his intentions perfectly clear. Dortmund were content with playing second fiddle for the time being and weren't yet ready to challenge Bayern.
In a column for the Süddeutsche Zeitung newspaper, Martin Schneider wrote this week that the Bundesliga, and specifically Bayern, need a strong Dortmund if they are to perform at the height of their powers.
"Bayern without Dortmund", he wrote, was like "Batman without the Joker" or, in a reference to the Star Wars movies, "the Galactic Empire without the rebels".
Neutral fans of Germany’s top division will be hoping Tuchel’s men present a bigger challenge next season.
And if Dortmund are hoping to wrestle their way back to the top of the Bundesliga it won't be Schalke, Wolfsburg or Bayer Leverkusen they'll need to beat: It'll be Bayern.