Anyone wishing to mark Chopin's ­bicentenary exactly had a choice. The composer maintained he was born on 1 March 1810, though his certificate of baptism gives the date of 22 February. The Southbank Centre has covered both bases. With Maurizio Pollini due to give a recital next week on the official 200th anniversary, the other contender for the title of greatest living Chopin pianist, Krystian Zimerman, appeared a week earlier, with a programme that included the second and third piano sonatas.

Zimerman's last British ­appearances, in 2008, suggested his ­peerless piano-playing is no longer quite as ­reliable as it once was. On this night, though the surface polish was there, it took a while for the performances to focus. The F sharp Nocturne Op 15 No 2 was routine, and even the first movement of the B flat minor Sonata was gruff, hurried and overpedalled. Then things gelled: the sonata's scherzo was ripplingly ­fluent, the funeral march full of magical ­colours and gradations, its ­transition to the ­enigmatic finale ­perfectly stage-­managed. An ­astounding account of the great B flat Scherzo Op 31 then ­followed – not as dramatically fierce as some ­performances, perhaps, but ­superhumanly controlled even through the ­ferociously demanding climax.

Zimerman seemed distracted during the B minor Sonata, repeatedly ­glaring at someone in the stalls, though his ­playing hardly ­suggested this. Everything was wonderfully ­supple, close to Dinu Lipatti's legendary ­recording but with an assertive edge to the finale, while the ­iridescent Op 60 Barcarolle was a ­demonstration both of Chopin's harmonic genius and ­Zimerman's gifts.