Leon Goretzka scored on his first appearance for four months as Bayern Munich romped to a controversial 4-1 win at Freiburg in a match overshadowed by a substitute mix-up on Saturday.
Four days before their Champions League quarter-final, first leg at Villarreal, Bayern put in a strong performance on the road.
However, there could be consequences for Bayern who briefly had 12 players on the pitch after a late double substitution.
“We drew the referee’s attention to the fact that Bayern had eleven outfield players on the pitch,” Freiburg director Jochen Saier told Sky.
“That was bizarre, I haven’t seen that before.”
Freiburg need to lodge a formal complaint for there to be repercussions for Bayern.
However, referee Christian Dingert noted the incident in his report and the official told Sky: “Now the DFB (German Football Association) must decide.”
Under league rules, such a breach of the substitutes regulations could even lead to the result being reversed.
When Niklas Suele and Marcel Sabitzer, who later scored, both came on in the 86th minute, only one player came off, leaving Bayern with 12 men on the pitch for 17 seconds.
“There was the bizarre situation,” admitted Bayern coach Julian Nagelsmann.
“The fourth official showed the wrong number and Kingsley Coman didn’t know he had to go off. Nothing decisive happened (during that time).”
There were then eight minutes of stoppage time after intense discussions between both benches and the referee.
Germany star Goretzka, who missed Bayern’s previous 13 league games with a hip injury, gave his team a second-half lead by heading in a free-kick.
Freiburg equalised when ex-Bayern striker Nils Petersen, who signed a contract extension Friday, hit the net just 17 seconds after coming on.
However Bayern pulled clear when Serge Gnabry, Kingsley Coman and Sabitzer fired in late goals.
Second-placed Dortmund can trim Bayern’s nine-point lead when they host RB Leipzig later.
Eintracht Frankfurt were poor ahead of Thursday’s Europa League quarter-final home leg against Barcelona in their goalless draw with Greuther Fuerth.
Home fans whistled the Frankfurt team as Eintracht failed to score against the league’s bottom club.
“That wasn’t good enough from us,” admitted Frankfurt’s Japanese captain Makoto Hasebe.
Head coach Felix Magath made a losing start on the Hertha Berlin bench as they slipped back into the relegation places after a 2-1 defeat at third-placed Bayer Leverkusen.
Magath was sidelined by Covid when Hertha ended a 10-match winless streak by beating Hoffenheim a fortnight ago, but the visitors lost with the former Bayern coach on the bench.
Lucas Alario put Leverkusen ahead when he fired home from a corner, then Karim Bellarabi added a second before Vladimir Darida pulled one back for Hertha just before the break.
Japan forward Takuma Asano scored both goals as Bochum dampened Hoffenheim’s hopes of qualifying for the Champions League with a 2-1 away win.
Both Asano’s goals came from passes by Bochum goalkeeper Manuel Riemann.
Germany head coach Hansi Flick was watching in the stands, the day after his team were drawn to face Japan in the World Cup.