The Bundesliga heavyweights edged the seven-goal showdown, but not without a proper scare from the flair-filled Sundowns, who showed why they've earned a reputation for playing some of the most attractive football on the continent.
Sundowns drew first blood through Ribeiro Costa, catching the Germans off guard early on. A goalkeeping slip from Ronwen Williams gifted Dortmund an equaliser, and the floodgates opened from there. The Germans took a commanding lead, aided by an unfortunate own goal from Khuliso Mudau, before Sundowns mounted a late fightback through Iqraam Rayners and Lebo Mothiba.
Despite the loss, Sundowns earned respect - especially from Kovac, who was vocal about the quality they brought to the pitch.
"As I said before, I wasn't just being polite - Sundowns really do play intelligent football," Kovac remarked post-match. "They're a technically well-drilled team with a clear philosophy. You can see the influence of their coach Miguel Cardoso - it's a bold, possession-based style."
Kovac acknowledged that while Dortmund were favourites on paper, the game told a different story.
"Yes, we were expected to win, but Sundowns pushed us to the edge. It wasn't easy, and that says a lot about their level. I have no doubt their next match will be another close contest."
With Dortmund now needing only a point against Ulsan HD to progress, Sundowns face a must-win clash against Brazil's Fluminense to keep their hopes alive. That game is set for Wednesday, 25 June at Miami's Hard Rock Stadium.
Though the scoreline didn't fall their way, Sundowns left the field with their heads high - and the football world watching.