Patience is a virtue in the Teatro Regio's marvellous Tristan und Isolde

Perhaps patience is required for full enjoyment of Tristan und Isolde. In 1891, Mark Twain attended a performance of Wagner's opera at Bayreuth, and recorded his impressions in notes published in the Chicago Daily Tribune. "When we reached home we had been gone more than seven hours," he wrote. "Seven hours at $5 a ticket is almost too much for the money." The Teatro Regio's recent production of Tristan might have provoked a similar reaction from Twain. With two 45-minute breaks between acts to allow for set changes, this was a long night featuring music that took a while to get into its stride.

Turin's Music Director Gianandrea Noseda has focused mainly on Italian repertoire since beginning his tenure in 2007, so it was always going to be interesting to hear him conduct Wagner. While the conductor's characteristic eye for detail was in full evidence on the night – music evocative of the sea teemed with detail early in Act 1 – the resultant vertical-rather-than-horizontal feel to this reading lacked inbuilt drive somewhat and did not initially convince.

That said, it was precisely such previously-absent aural cohesion and flow that characterised much of what followed. Act 2 opened stirringly, and offered no opportunity to pause for breath as the orchestra hurtled inexorably towards the lovers' music and on to their discovery by King Marke in a single unbroken arc. What distinguishes Noseda's Tristan most of all, however, is especial orchestral balance and a transparency of sound that reveals the inner workings of the music. The subterranean groans in the prelude to Act 3 sounded less laboriously carved out of onyx as delicately outlined in charcoal pastels.

Stefan Vinke's Tristan also took some time to get into his stride: he sounded tight and, consequently, dulled and under the note for much of the first two acts. But he did possess the stage presence required in a production in which much of the erotic tension is generated by placing Tristan and Isolde at large distances apart, for example at either side of a long dining table, and in Act 3 Vinke found another gear musically, his voice springing to life as he railed ferociously against his fate.

Rachel Nicholls' Isolde was, in contrast, superlative from the start. She sounded spectacular, combining a silvery sheen with an iron core in lines that unravelled with a wondrously even legato, and was fully convincing dramatically. The Liebestod grew from a whisper to free-flowing mantel of sound. Its ecstatic quality worked its way into your bones.

Director Claus Guth places the action in the bourgeois household somewhere near the turn of the 19th century. His concept felt somewhat cold and detached at first, and a number of details, for example the decision to dress Isolde and Brangäne in the same clothes, felt abstruse. But symbolism elsewhere was subtly effective: Tristan lost in thought and turning a bedside lamp on and off – an allusion to Wagner's Apollonian-Dionysian dichotomy between day and night – hints at the hero entertaining the idea of attempting to reconquer Isolde even before he has drunk the contents of Brangäne's vial.

Indeed, like a slow-working love potion this production won me over gradually. The revolving stage, put to good use throughout, is not merely a convenient means for switching between scenes but the pillar of Guth's concept. Rooms with contrasting qualities – a dining room dominated by a long table, a rippingly-lit corridor for the love duet, a green house in which the lovers search for another between the foliage – float into view, forming a labyrinthine structure in which Tristan and Isolde partake in an erotic hunt in which the prospect of them being united is often distant. Here, Wagner's Schopenhauerian metaphysics, namely his meditation on the unachievable nature of man's desires, are given full voice.

The remaining leading roles were strongly cast. Steven Humes makes an authoritative, noble King Marke, whose discovery of Tristan and Isolde's affair was at once dignified and heart-rending. Martin Gantner brought Kurwenal to life, and Michelle Breedt was a powerful Brangäne. Those in the audience that made it to the end of this performance sounded well-pleased.