Bale was introduced in the second half of the match and scored quickly upon entering the fray.
He scored Real's third and final goal in the 3-1 win over the club's crosstown rivals, and the finish was his 100th for the club.
However, it was a finish that ended in controversy as Bale was reported to authorities for “a gesture of possible obscene and derogatory meaning” as a result of the ensuing celebration.
Bale was pictured gesturing towards the direction of fans on the sidelines, seen as a provocation by La Liga.
A statement from La Liga read: “In the 73rd minute of the game, after scoring his team's third goal, Real Madrid player Gareth Bale, who had been booed by the local fans, celebrated by raising his right hand close to his head, in a provocative gesture to the supporters, then in a gesture of possible obscene and derogatory meaning doubled his arm while cutting across the middle of it with his other hand.”
The statement went on to say that Bale could be suspended for "four to twelve games" with the more likely suspension being said to be a month.
However, the incident was not reported by the referee in his match report and the Spanish federation have opted to not punish the Welsh winger for the celebration at all.
It's not the only celebration row Bale has found himself in recent weeks, having also earned criticism for pushing away Lucas Vazquez after scoring from the spot in this past weekend's win over Levante.
Vazquez approached Bale to congratulate him after scoring what ended up being the match-winning penalty but was quickly rebuffed by his team-mate.
Bale has been with Madrid since 2013 and has scored 101 goals in 220 appearances for the club, including 13 goals in 31 appearances this campaign.
He has been named in Santiago Solari's latest 20 man squad to face arch-rivals Barcelona on Wednesday, in the quarterfinals of the Copa del Rey.