St Petersburg Philharmonic Orchestra, Royal Festival Hall, London

The orchestra played on

Diamonds, pearls, tails, stilettos, past and present government ministers, ambassadors, flunkies, and tickets costing up to £200 all spells "unusual". Indeed this fund-raising event for the St Petersburg Philharmonic Orchestra at the South Bank turned out to be substantially more unusual than the organisers had planned.

On paper, the event was set to present a roll-call of the most illustrious musical talent drawn from the lands of the former Soviet Union, taking part in a virtual circus of bleeding musical chunks. But then it all began to unravel. Exit Maxim Vengerov sick, and Olga Borodina with hay-fever – two out of five stars felled. Miraculously, instead of catastrophe (the withdrawals were virtually on the day) a real concert emerged, the protagonist – the orchestra – rightfully gaining centre stage.

And helping the baffled audience (who had shelled out a fiver for a programme that was now seriously misleading) was a masterful cheerleader – no last-minute substitute, but the seriously funny comedian of St Petersburg conception (born London): Sir Peter Ustinov. The Gods were smiling. After a positively fizzing Festive Overture by Shostakovich, it was clear that the orchestra was playing for its life. Sitting in an unusual (but Russian) configuration – double basses to the left, brass to the right, wind centre, percussion behind – the St Petersburg orchestra gave as astonishing a display of virtuoso playing as has ever hit the Royal Festival Hall. And acoustically, it sounded marvellous – British orchestras note!

Music Director Yuri Temirkanov is clearly a magician: here is an orchestra whose members palpably enjoy playing not just with each other but also for each other. The long first-half paraded soloists: violist Yuri Bashmet playing a dull Romance by Bruch, Dmitri Hvorostovsky wowing the audience with his shapely phrases and breath control in Verdi and Tchaikovsky, and Evgeny Kissin performing the 1st movement of Tchaikovsky's B flat minor concerto.

Whether Kissin feels safe in the avuncular hands of Temirkanov or particularly safe in Russian repertoire with a Russian orchestra, his playing displayed unusual emotional engagement.

But then seldom is Tchaikovsky played with so much feeling and so little sentimentality. And it was this strength surely that led the audience spontaneously to applaud – mid-movement – the orchestra's flawless "Swan Lake".

It felt like deprivation to be offered only four movements from Tchaikovsky's Suite but we were rewarded with the (unscheduled) whole of Tchaikovsky's 4th symphony. The orchestra moved like a single unit, swelling and surging, natural rubato raising tension, pacing and placing impeccably judged.

It felt like perfection and then came the encores: touchingly Elgar's "Nimrod" – a special gift at a special time – and, after three hours of playing, Prokofiev's "The Death of Tybalt" at an insane speed. Death defying, of course.