Freiburg top the Bundesliga thanks to a dramatic 3-2 win at Bayer Leverkusen saw them take the opportunity presented by champions Bayern Munich drawing 1-1 at Union Berlin on Saturday.
Either Union or Bayern would have jumped Borussia Dortmund – who defeated Hoffenheim 1-0 on Friday – to go top with victory but shared the spoils.
Freiburg looked to have taken their chance thanks to early second-half goals from Matthias Ginter and Michael Gregoritsch cancelling Kerem Demirbay's opener before Patrik Schick headed an equalizer.
But substitute Ritsu Doan's late winner took Christian Streich's top on goal difference from Dortmund, with Union and Bayern each one behind their best tallies of 12.
Sheraldo Becker's fifth goal in five games had put Union provisionally top for the first time in their history but Joshua Kimmich's deflected strike ensured the dream last only three first-half minutes.
Eintracht Frankfurt thrashed fellow Champions League side RB Leipzig 4-0 in the late game with Augsburg v Hertha Berlin and Borussia Mönchegladbach v Mainz the Sunday ties.
A minute's silence was observed before the kick-offs to commemorate the 50th anniversary of the 1972 Munich Olympic massacre.
Union struck early in the battle at the top when Becker volleyed in Christopher Trimmel's 12th minute free-kick but their failure to clear a corner presented Kimmich with an immediate, though fortunate, leveller.
"Overall we didn't have the energy level of the last weeks," said Bayern coach Julian Nagelsmann, following a mid-week German Cup game and ahead of Wednesday's Champions League opener at Inter Milan.
"We weren't 100% awake in the head in certain situations."
Frederik Rönnow made a superb save to deny Leroy Sane and tipped over from Sadio Mane in injury-time to earn a point for the Berliners, who are yet to beat record champions Bayern in the Bundesliga.
"Defensively we showed an absolute top performance," said Union boss Urs Fischer. "Although Bayern had 70% ball possession, we were never passive."
Ginter headed in a corner, Gregoritsch took advantage of an error and Doan was then on hand for a back-post tap-in, from another corner 18 minutes from time, to take Freiburg top.
"We scored two set piece goals," said Streich. "Overall it was a lucky win because Leverkusen had more chances.
"It's going for us at the minute but I can still classify the result correctly."
Leverkusen have made a poor start to the season and are 13th after four losses in five league games and a first-round exit from the German Cup.
Sporting director Simon Rolfes, however, said coach Gerardo Seoane "of course has our full backing and trust, no question."