When Castorf, the 61-year-old enfant terrible of German theatre, took his curtain call at the end of the six-and-a-half-hour evening, he was met with an deafening chorus of boos and whistling from the audience of nearly 2,000 people.
Initially, he and his production team stood motionless, but Castorf soon started pointing at the audience and then tapping his forehead, in a gesture of clear provocation.
It was the first time during his new staging of Wagner's monumental "Ring" cycle that Castorf had actually shown himself in the legendary Festspielhaus theatre that hosts the world-famous month-long summer festival dedicated exclusively to the composer's works.
The 16-hour cycle is made up of four operas – "Rhinegold", "The Valkyrie", "Siegfried" and "Twilight of the Gods". And it is a tradition in Bayreuth that the director does not take his bows until all four operas have been premiered.
Two of the singers also faced the audience's disapproval: Canadian tenor Lance Ryan, who sounded strained and tired in the role of Siegfried, one of the most demanding roles in the repertoire; and Korean bass Attila Jun, who was disappointing in the role of the evil Hagen.
By contrast, British soprano Catherine Foster, making her Bayreuth debut as Brünnhilde, was feted for her unusually lyrical interpretation.
But it was Russian maestro Kirill Petrenko, also a debutant on Bayreuth's Green Hill, who proved the star of the evening, as he had in the three earlier instalments of the "Ring".
Castorf, notorious for his anarchic reinterpretations of the great classics of theatre, but a relative newcomer to music theatre, had been chosen to direct a new "Ring" for Bayreuth, one of the most hotly anticipated events in the Wagner bicentenary year.
But he had already tried to play down expectations in the run-up to the festival, arguing that he had not had sufficient time.
He was only brought in two years ago after the German film director Wim Wenders who was originally to have staged the "Ring", pulled out.
While Castorf's reading was highly cinematic, with the fast-paced action of a Quentin Tarantino movie, his direction also proved patchy in parts.
The Bayreuth Festival continues on Thursday with a revival of another controversial staging, this time of "Tannhäuser".
The festival runs until August 28th and tickets are notoriously difficult to come by with the waiting list stretching to 10 years and even more.