Of the seventeen operas Handel wrote to star the Italian castrato Senesino, Giulio Cesare in Egitto is the most popular, and the one performed most often. It is a dramma per musica filled with ironic hints, and based on power and sex intrigues in ancient Rome. The 38-year-old Handel wrote it in England when his imported Italian-style operas started to fall out of favour.

This production in the opulent Palais Garnier is almost the same as it was when it was last performed here two years ago: the stage set is the storeroom of a museum in Cairo, filled with huge, ancient statues, wrapped or unwrapped, which come alive, moving and singing. Various periods of history are juxtaposed while museum workers bring in and take away antiques, moving them continually and interfering with the action.

The stage director and costume designer, Laurent Pelly, whose imaginative staging of Rameau’s Platée in the same place is still remembered, took a risk this time by opting for only one setting, instead of the twelve imagined by Handel. And by his emphasising opera buffa elements, the singers were often overshadowed by the comedy, at the expense of character development.

We can easily imagine the immensity of the challenge faced by the cast (especially the countertenors) when we consider the cavernous acoustic of the Palais Garnier, designed in the 19th century primarily for ballet, and certainly not for Baroque opera. The auditorium is furnished with a heavy carpet – infamous for dampening acoustics, and of a kind no longer to be found in any other Parisian opera house.

But despite the unimaginative staging and colossal demands on the cast, as well as the absence of Natalie Dessay (who took the star role of Cleopatra two years ago), the dramatic tension and the audience’s attention were successfully held for almost five hours, mainly thanks to the outstanding vocalists.

The most convincing were the two countertenors, each one brilliant in his own way: the moving and sophisticated Lawrence Zazzo in the title role, and the wild and thrilling Christophe Dumaux as Tolomeo. And not to mention the exquisite Armenian mezzo Varduhi Abrahamyan, who totally eclipsed all previous Cornelias.

Lawrence Zazzo as Cesare, in a monochrome costume a living statue of the emperor, sang with thrilling vocal subtlety, precision and sense of nuance, and managed with a unique grace to escape from the ambient stiffness and the one-dimensional, cartoonish nature of the stage director’s reading of this part. His expressivity was measured, and his coloratura more rounded and dazzling than ever before. The refinement of his velvet timbre, strong low register and effortlessly rendered legatos made even the risky and revealing “Empio, diro, tu sei” sound flawless, sincere and free from heavy Baroque formalism.

In the love duet “Caro, bella!” with Sandrine Piau (Cleopatra), Zazzo successfully brought to life Cesare’s most fragile and human side with natural grace and maturity without ever succumbing to maudlin gloom. Sandrine Piau, in the role of Cleopatra, was almost convincing as the infatuated Egyptian ruler, though her opening “Non disperar” lacked sparkle and her coloratura was often too close to the sharp side.

As Cleopatra’s brother Tolomeo, French countertenor Christophe Dumaux demonstrated once more why several opera companies insist on having him in this role. His Tolomeo in last year’s scandalous Cesare production at the Salzburg Festival highlighted his huge theatrical talent and remarkable vocal capacity, often unjustifiably left in the shadows. Without a doubt the best French countertenor, as René Jacobs recently remarked, Dumaux never gives a performance that lacks personality. And though Pelly’s staging and costume reduced Tolomeo to an almost comic character, Christophe Dumaux, with his unique and dazzling alto timbre, virtuously rounded in the middle and low ranges, successfully reminded us one more time that Handel’s works are primarily all about flesh, blood and passion.

Mezzo-soprano Varduhi Abrahamyan was one of the best Cornelias I have ever heard and, just like Christophe Dumaux, certainly deserves much more attention from opera companies. Karine Deshayes sang Sesto without the requisite emotional involvement and depth, thereby failing to persuade us that “Svegliatevi nel core” and “L’angue ofesso mai riposa” are among the most inventive and vibrant melodies Handel ever wrote. Dominique Visse with his inimitable timbre, was, as always, a perfect Nireno.

Though Emannuelle Haïm’s hefty and all-too-often harsh conducting sometimes lacked nuance – and, oddly enough, suited Laurent Pelly’s staging – this production of Giulio Cesare is still opera to savour.