Atletico Madrid edged the Spanish capital derby against rivals Real Madrid, sealing a 2-1 win on Sunday evening in a top-of-the-table clash from the seventh round of the LaLiga season.
Footage of referee Ortiz Arias sparked widespread controversy after the final whistle. He appeared to leave the pitch smiling, just as anger gripped Real Madrid's players and fans over a series of contentious refereeing decisions during the derby.
The official account of the programme "El Chiringuito" wrote on "X": "Ortiz Arias, the referee of the derby match, is leaving the pitch laughing".
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Controversy trailed the game throughout, with Real Madrid furious that no red card was shown in more than one incident during the first half.
Two moments stood out. Cuti Romero caught Jude Bellingham, then Kang-in Lee went in on Federico Valverde. Real Madrid's channel argued both tackles deserved a red.
Send either player off, the channel reckoned, and Atletico would have been down to nine men. Ortiz Arias produced nothing for either challenge before the break.
The second half told a different story. Real Madrid defender Dean Huijsen saw red after a tackle that needed VAR intervention, leaving the Royal side to finish with ten men.
Those decisions lit the fuse after the final whistle, all the more so given Real Madrid's 2-1 defeat to their neighbours in a derby packed with heavy tackles, clashes and calls open to debate.