Bundesliga Round-Up: Alcacer hat-trick helps Dortmund to thrilling win
Having already scored two late goals off the bench in last Saturday's 4-2 comeback victory at Bayer Leverkusen, and netted again in the 3-0 Champions League win over Monaco on Wednesday, the 25-year-old Alcacer, on loan from Barcelona, again proved deadly off the bench.
In front of 81,365 fans at Signal Iduna Park, Dortmund slipped 1-0 down after Alfred Finnbogason's first-half goal.
But Alcacer equalised in the 62nd minute, just three minutes after coming on, with the Spain international smashing home a cross by teenage winger Jadon Sancho, who was called up by England on Thursday for the first time.
Philipp Max restored Augsburg's lead by taking advantage of some poor Dortmund defending, only for Alcacer to claim his second equaliser on 80 minutes when he fired in off the post.
Dortmund led for the first time on 84 minutes when midfielder Mario Goetze, another second-half replacement, latched onto a great through ball and fired home on his first Bundesliga appearance this season.
The game swung again as Augsburg equalised when Michael Gregoritsch headed home a Max cross to make it 3-3 with just three minutes left.
However, the stage was set for Alcacer to seal the three points after Augsburg's Sergio Cordova gave away a free-kick.
The stunning win means Niko Kovac's Bayern Munich, who trail Dortmund by four points down in fourth, cannot regain top spot even if they later beat Borussia Moenchengladbach at the Allianz Arena.
Elsewhere, Hertha Berlin missed the chance to claim second from Werder Bremen, who won 2-0 at Wolfsburg on Friday, as they were held to a goalless draw at Mainz.
Hertha captain Vedad Ibisevic missed a great chance when he hit the Mainz woodwork with a first-half chance.
After losing their first five games, Schalke continue their rise up the table with a 2-0 win at Fortuna Duesseldorf.
US international Weston McKennie who scored in their 1-0 Champions League win at Lokomotiv Moscow in midweek, and Guido Burgstaller grabbed Schalke's goals to put them 14th.
US striker Bobby Wood scored with two perfectly-timed headers as Hanover 96 picked up their first win of the season with a 3-1 home win against Stuttgart.
Wood gave Hanover the lead when he guided a header inside the far post after 30 minutes.
The 25-year-old added a second just before the break with another bullet header, expertly guided past Stuttgart's goalkeeper.
Former Germany striker Mario Gomez, with a bandaged head after a first-half clash, scored Stuttgart's consolation goal soon after the break before Hanover's Togo striker Ihlas Bebou added their third in the 91st minute.