Manon, Royal Opera

You'd be forgiven for thinking that an opera that - in all seriousness - climaxes to the words, "Farewell, little table. You seemed so large," might need a small, but firm, slap in the face. But you'd be quite wrong. Manon is really quite froth-free.

Coursing through the work was one basic idea: the helter-skelter philosophy of the diagonal, of the slide, of the see-saw. Everyone in Manon is rising or falling. It dictates Chantal Thomas's simple, bold set design, which sinks or swells at every turn - down to the banks of the Seine, up to the lovers' suspended garret home, up and down the ramped casino. It dictates the decision to relocate the drama from the reign of Louis XV to the great French capitalist roller-coaster ride that was the Second French Empire.

No one is taken on a more vertiginous journey than Manon herself and nothing should be more unpredictable than Manon's handling of these new terrains. And, yet for all Netrebko's attributes, for all her immense skill (her vocal control is better than ever), she just didn't go that extra loony mile that's necessary to really believe in this character's wild fate. She was neither wide-eyed enough in the first act, nor manipulative enough in the second, nor desperate enough in the final two. Inevitably, her diva moment in Act Three came pretty naturally to her. But, as always, where the physical and psychological fail with Netrebko, the voice takes over.

The same was largely true of Grigolo's debut as Chevalier, whose fearless singing more than made up for the shortcomings in his acting. It wasn't something I noticed at first. His firecracker Act One entrance, part puppy, part bull, seemed just right for sweeping Manon off her feet. Even the 10 minutes of embraced circling, which should have looked ridiculous, actually followed on naturally from his hurtling energy, like a spinning weather-vane in the wind. But this breathlessness needed to stop, or at least mutate or mature as life dealt its many blows to the relationship. And yet it never did.

Beyond the two leads, the cast had depth and strength, particularly in the superb leering and operetta-like singing en pointe from William Shimmell (de Brétigny) and Christopher Mortagne (Guillot), and the stentorian offerings from Christof Fischesser's Comte. The actress trio, Pousette (Simona Mihai), Javotte (Louise Innes) and Rosette (Kai Rüütel), were a French Rhinemaiden-like delight. We had to wait until the duet in the third act for the vocal and amorous touchpaper to be well and truly set alight between the lead couple, a now ordained Grigolo ripping off his vestments for a bit of vestry nooky.

Antonio Pappano was equally passionate with the orchestra, ripping into the score, scooping out the colouristic flesh, rolling out the salty seaside swells and plunges, pushing on the almost Wagnerian romantic lapping. Neither Pelly nor Pappano could have made a better case for this piece or the composer, and its importance to the 20th century. The impressionistic third act, a Manet-like combination of the blurred and the razor-sharp, and the expressionistic fourth, The Cabinet of Dr Caligari in feel, was surely emphasising this.

It was a shame that the leading couple didn't invest the psychological aspect with as much attention as Pelly and Pappano had done the dramatic and musical. The audience were riotous in their indifference to this point, cheering the leads to the rafters. No metaphorical slapping then from the audience for this opera, and a hell of a lot of love and metaphorical knicker-throwing for Grigolo. We'll no doubt be hearing more from this young Italian. I hope he got home safe.

• Manon continues until 10 July 
• See the 2009-10 Royal Opera House season
• See the 2010-11 Royal Opera House season