Dortmund travel to Munich with a two-point advantage over their title rivals after Bayern surprisingly dropped points against Freiburg last time out.
With only six rounds of games remaining after Saturday's match at the Allianz Arena, a win would be a huge boost for either side.
Hitzfeld – who coached Dortmund between 1991 and 1997 before two spells in charge of Bayern – expects a fierce battle, but believes the current pacesetters have an advantage given the last-gasp nature of their win against Wolfsburg last weekend.
They appeared to be heading for a disappointing draw before two stoppage-time goals from Paco Alcacer handed them all three points.
"The momentum is in Dortmund's favour because they just had a sense of achievement in their last match," Hitzfeld told Omnisport.
Paco Alcácer, game-winning free kick maestro pic.twitter.com/P9rTxi0Lsg— Borussia Dortmund (@BlackYellow) April 4, 2019
"In the last few minutes they score two goals. This, of course, brings self-confidence and that brings a special mood. And you have seen that too. They even released pictures from the dressing room as the players celebrated. This is something really special.
"And Bayern suffered a setback in Freiburg, although in my view Bayern did not play badly. They were clearly superior and had many chances, but they did not score."
Bayern scraped past second-tier Heidenheim 5-4 in Wednesday's DFB-Pokal quarter-final, albeit having played much of the game with 10 men, leading to coach Niko Kovac warning his players that they need to show defensive "discipline and responsibility" against Dortmund.
That is an assessment Hitzfeld agrees with and the 70-year-old believes Bayern could be in a for a difficult game if they do not tighten up at the back.
"The deciding factor will be for Bayern to get back their stability," he added.
"It will be a special challenge for Bayern’s defence. They need to perform as a team, not just the defence but also the midfield and the attack. All 11 players need to work well.
"They must try to keep the danger away from their goal and need to attack early so that Dortmund have trouble getting into their rhythm.
"Continuity and confidence are missing as they’re not used to being the ones chasing. That has left marks on them. You can tell as they find it difficult to have a relaxed approach to matches."