You might wonder why the two jewels in the crown of the Russian Federation's performing arts scene decided to launch unorthodox residencies in London at the same time. As it is, the word on the street (or in the stalls) on the Mariisnky Theatre's stay at the London Coliseum and the Bolshoi's residency at the Royal Opera House is that this was a case of opportunistic rivalry: Valery Gergiev of St Petersburg's Mariinsky Theatre booked the Royal Opera House only to discover that his programming idea - a mini-festival marking 100 years since the birth of Dmitri Shostakovich - wasn't compatible with the terms of his Covent Garden contract, so he cancelled. Enter stage left the Bolshoi Company from Moscow, who filled Gergiev's vacancy with a scheduled run of operas and ballets lasting over three weeks. Gergiev however wasn't to be outdone, and booked the London Coliseum, home of English National Opera, for a shorter run of nine days - but one that would start before the Bolshoi had even touched down at Heathrow.

And this isn't where the off-stage character curiosity ends. Gergiev is feted by the worldwide press as one of the greatest conductors alive, a reputation which led the bold-as-brass London Symphony Orchestra to bag him as their Principal Conductor from January 2007 in a move which was reminiscent of Roman Abramovich's spending spree at Chelsea. It's acknowledged that the LSO does have something of a relationship with the Russian maestro, but one wonders if that relationship will ever reach the extraordinary creative dynamo that is the Gergiev/Mariinsky partnership. It'll be a great disappointment if it doesn't, but if it does, London audiences have a great deal to look forward to.

One of Gergiev's greatest assets is his unparalleled ability to create an atmosphere - even when confined to an orchestra pit as in the Mariisnky's performance of Shostakovich's opera Katerina Izmaylova. Even before a note had been played this frowning, unshaven character had the audience at the Coliseum in the palm of his hand; the anguish of Shostakovich's opera (a pruned version of his acknowledged masterwork, the outspoken Lady Macbeth of Mtsensk District) unfolded it seemed in reverse and oozed upwards from the orchestra pit and onto the stage, the conductor's fluttering fingertips coaxing extraordinary detail and rivetting volume from his players. Dramatically this was an effective but polite performance, and with the declamation of Shostakovich's preferred original Lady Macbeth in mind, the detail on-stage didn't pack a punch - perhaps the company was happy to rely on its ability to muster a musical rendition of the work that would have London institutions crying into their scores. With similar quality in the dramaturgy this would have been a performance of tremendous synergy and power, and a truly unforgettable event.

And so to Covent Garden, where the Bolshoi presented a visually striking performance of Prokofiev's The Fiery Angel which was engaging from its outset, not only for the unashamedly loud but still refined noises flowing from the pit. Like a vision of Moscow against one of St Petersburg, the Bolshoi appeared brash against its compatriot company - though in Prokofiev's nightmarish tale of evil spirits and hopeless commitment the impertinent vernacular of horror seen on stage was a welcome counterpoint to Prokofiev's often frantic and purposefully claustrophobic score. Fine vocal and dramatic performances from Boris Statsenko as Ruprecht and Tatiana Smirnova as Renata stood out from a quality ensemble. It's a testament to Gergiev though that the Bolshoi couldn't match his atmosphere despite quality in all areas.

With all the talk of Russia's socio-economic decline, it would be naïve and vaguely insulting to the struggling elements of Russian society to attach political significance to the quality of these two companies' performances in London; in the west we've thankfully moved on from the age when your country's civilisation rating depended on its ability to produce a decent opera, though as the Mariinsky Theatre emerges resplendent from the crumbling backstreets of St Petersburg, the plot in Russia could appear somewhat different. Then again, there's a naturalness to the way the Russians do these things which suggests their institutions are propped up only by innate talent; these musicians have a knack of making you feel like the rest are no more than talented amateurs. We'll know in a few years whether Gergiev's work at the LSO can have the same effect.