Debutants Oliver Burke and Naby Keita combined to earn RB Leipzig their maiden Bundesliga win as they stunned Borussia Dortmund 1-0 at the Red Bull Arena.
Scotland international Burke set up Keita to score late in the game, after Dortmund had been outplayed by their promoted hosts.
It looked as though Leipzig would have to settle for a draw, as both Timo Werner and Marcel Halstenberg were denied with two of the game's best opportunities in the last 10 minutes.
Andre Schurrle then ran clear, only to strike the crossbar, and the home side punished Thomas Tuchel's men for their profligacy.
Champions Bayern Munich won at Schalke on Friday, but last season's runners-up could not keep pace, falling three points behind after two rounds of the 2016-17 league campaign.
A number of visiting fans missed the game in protest at Leipzig's Red Bull ownership, and the home supporters undoubtedly left the happier.
Making his second debut for the club, Mario Gotze won an early free-kick on the left and the resulting neat move saw Schurrle's shot deflected wide of the near post.
As Dortmund toiled in the early stages, their next chance was also directed off target, with Pierre-Emerick Aubameyang dangling a leg at a cross.
And the first save of the game had to be made at the other end by Roman Burki, when Dominik Kaiser teed up Werner to thump into the goalkeeper's hands.
On the half-hour mark, the visitors belatedly forged a first clear sight of goal, but, after a neat move ending with Gotze's lay-off, Schurrle whipped his finish beyond the post from the edge of the area.
Both teams resorted to strikes from distance as the first half drew to a close, with Leipzig enjoying a number of unsuccessful forward forays.
Understandably disappointed by their efforts before the break, Dortmund came back out in determined fashion, but the hosts' physical approach continued to nullify their attacking threat.
With just over 20 minutes remaining, and chances at a premium at either end, Burke, Leipzig's big-money buy from Nottingham Forest, was introduced for his debut in the hope of stealing all three point.
He was immediately joined on the field by Dortmund's own young talent Ousmane Dembele, who had an immediate impact in creating crossing opportunities for his team-mates that were again squandered.
Werner was now getting joy on the right, though, first firing into the side-netting, before being freed by Burke to bring a fine stop from Burki.
From the subsequent corner, Leipzig came closer still, with Raphael Guerreiro clearing Halstenberg's header off the line.
Dortmund looked certain to win the game in the final stages as Schurrle bore down on goal, but his finish was high and clipped the crossbar on its way over.
And, in quite stunning fashion, Leipzig stole victory. Burke crossed from the right for fellow substitute Keita to ram a finish into the roof of the net.