And she was wise in so doing, for her incarnation of Wagner’s most demanding woman was clearly the sensation of the SFO season.

Although a major Ariadne for the past decade, Brewer had never sung a note of Isolde in public until 2000, when she performed the role in concert — one act an evening — with the BBC Orchestra at London’s Barbicon. Critics celebrated that event as the best Wagner heard in the British capital in four decades. Brewer then did Isolde — again an act at a time — with Esa-Pekka Salonen and the Los Angeles Philharmonic in Peter Sellars’ “Tristan Project.” Only in August 2005 did she put it all together for the first time in a concert “Tristan” at the Edinburgh Festival. Jonathan Nott conducted the Bamberg Symphony. And prior to the San Francisco debut she recorded the “Liebestod” with Donald Runnicles and the Atlanta Symphony and a complete “Tristan” with the BBC Orchestra and Runnicles for Warner Classics with. John Treleaven as Tristan.

Brewer’s approach to a new role — the subject of many interviews with the soprano — focuses intensely on the text divorced from the music. She reads it over and over in the original language and then in her own literal translation. At the SFO the success of her method was underscored by the profundity that she brought to the exposition of the opera’s plot. For many singers Isolde’s recall of her earlier meeting with Tristan, how she spared his life and nursed him after he had killed her betrothed Morold, is something to be gotten through before delivering the curse upon them both. In her reconstruction of events Brewer made clear that this is the heart of “Tristan.” The love potion and what follows are only the unraveling of the tale spun here. Her growing agitation demanded shipboard confrontation with Tristan, without which everyone would have lived unhappily ever after.

Brewer is not one to wear her heart on her sleeve. Isolde’s torment seethed within her, and she laid bare this tempest of pain and passion step by step, building half the first act to the curse, which she delivered with shattering fury. Yet she sang the curse — just as in Act Two she sang the plunge of the torch into the abyss. She did not declaim; she eschewed Sprechstimme, and there was radiant beauty in every note.

Although American Thomas Moser will hardly go down in music history as a great Tristan, at the SFO he was very good in the role — solid and fully reliable. And he had the stamina to carry through to the end of Act Three — even in this uncut performance heard on October 10. Soon to sing Parsifal in Vienna with Runnicles on the podium, Moser is a tenor of taste and intelligence and a near-ideal partner for Brewer.

In this production Israel-born bass Boaz Daniel made his North American debut as Kurvenal, the role that he sang both in the BBC concert “Tristan” and on the Warner recording. He was the loyal servant of his master without overplaying his obedience, and in Act One his mockery of Isolde was comfortably low key. Daniel seems destined to be heard in leading roles for decades to come.

And it is not size alone that made Kristinn Sigmundsson a monumental King Marke — although the bass from Iceland is of dimensions that suggest Fafner and Fasolt in a single figure. And the voice is of equal proportions. In keeping with the overall perspective of this staging Sigmundsson’s second-act lament spoke not of self-pity, but of a deep and painful wound — something beyond his comprehension. (During the season Sigmundsson also sang a Sparfucile in the SFO “Rigoletto” that made the figure even more sinister than Verdi perhaps intended.)

England’s Jane Irwin, a regular in several European “Ring” productions, made her North American debut here as Brangäne. Her second-act warning to the enraptured couple floated with lilting lyricism into the reaches of the War Memorial Opera House.

Matthew O’Neill and Sean Pannikar, members of the SFO Adler studio, sang Melot and the Shepherd; veteran chorus member Jere Torkelsen was the steersman.

Thor Steingraber directed this re-staging of David Hockney’s production, new at the Los Angeles Opera in 1988. Hockney’s stunning use of primary colors, along with regally stylized costumes, complemented the static nature of Wagner’s score, a quality that allegedly prompted actress Beatrice Lilly to observe after Act One that for Germans love was obviously a state roughly akin to paralysis.

Much, of course, could still be said about this “Tristan” — the hurricane force of desire behind the “Liebesnacht,” the eye-moistening authenticity of lament in the “Liebestod, but what made it even greater than the sum of its many superb parts was the continuity brought to the work by Runnicles, one of today’s top Wagnerian conductors. Runnicles, praised in England as “a psychoanalyst summoning Leitmotivs like hidden memories,” allowed Wagner’s score to unfold with full force. For him this is true music drama, not an assembly of “greatest hits” separated by seemingly interminable — and thus often abbreviated — dialogue.

The SFO staging further profited from the fact that most members of the cast had been involved — in various constellations — in the “Tristan” productions in Edinburgh and London. Their interaction recalled the glories of ensemble perfection in the pre-jet-set age.

Runnicles, by the way, has announced his decision to leave the SFO music directorship at the end of the 2008-‘09 season. He has held the position since 1992.

Wes Blomster