Joshua Kimmich apologised for his "unsportsmanlike" behaviour after celebrating Bayern Munich's win over Freiburg in front of the home fans.
Bayern edged Saturday's tight Bundesliga contest 1-0 at Europa-Park Stadion thanks to Matthijs de Ligt's long-range strike early in the second half.
The victory came four days on from Bayern's elimination from the DFB-Pokal to the same side, which Freiburg took delight in reminding their opponents before the match.
Kimmich clenched both fists and gestured towards home supporters after Bayern exacted some revenge on Saturday, causing a mass confrontation on the pitch.
Freiburg midfielder Nicolas Hofler accused Kimmich of "unsportsmanlike and unnecessary" conduct and added his opposite number "should not feel the need to provoke fans".
When Hofler's comments were put to Kimmich after the match, the Germany international accepted he perhaps went too far with his celebrations.
"There were many emotions involved," he told reporters. "It was an important win for us – the DFB-Pokal defeat hurt deeply.
"I got carried away; I shouldn't be doing that. You can say it was unsportsmanlike."
Asked what provoked his actions, Kimmich added: "During the warm-up, there was a 10-minute film about the Pokal game being shown [on the big screen].
"I can understand anyone who describes [my reaction] as unsportsmanlike. In the end it's just emotions."
Thomas Tuchel's side wasted some big chances either side of De Ligt's strike, but were also reliant on goalkeeper Yann Sommer producing a couple of important saves.
Freiburg were previously unbeaten in a club record 12 home games, but Bayern did enough to come away with a win that keeps them two points clear of Borussia Dortmund.
"We knew it would be a difficult game," head coach Tuchel said. "They were 12 games unbeaten at home and beat us in the Pokal midweek.
"In the end, I think the win was deserved. We had big chances to score in both halves. I'm happy that we won and kept a clean sheet. It was so important."
De Ligt's long-ranger, which took a touch on its way past Mark Flekken, generated an expected goals (xG) value of just 0.02.
The centre-back took particular delight in scoring past his Netherlands international team-mate, who made seven saves either side of that winning goal.
"I always score against Mark in training, so I thought I'd just give it a try," De Ligt said. "Our performance was good, but we still have a lot of room for improvement."
Bayern have won two of their three games since Tuchel took charge and now turn focus to the first leg of their Champions League quarter-final with Manchester City.
"We have to be brave. We have to believe in ourselves, be smart, have tactical solutions and go to the limit of our physical efforts," Tuchel said of Tuesday's tie in Manchester.
"City have been playing at an absolute top form for weeks. We need to regenerate and hope to have everyone fit."