Dance Manon / Royal Ballet Royal Opera House, London

Prostitution, pimping, gambling, theft, foot-fetishism, murder: Manon is one of Kenneth MacMillan's "adult ballets". Not that there is anything more offensive in this 1974 adaptation of Trevost's Manon Lescaut than the ludicrous melodrama of some of MacMillan's choreography. The overtly sexual gymnastics and cloyingly histrionic flavour of the love duets between Manon and Des Grieux offer a kind of passion by proxy for the most susceptible and obsessive kind of balletomane. Yet next to the monotony and uninventiveness of MacMillan's dances for the beggars, harlots and other characters, these duets also seem like the ballet's most committed and incisive passages. And, if the dancers playing Manon and Des Grieux are carefully matched, their on-stage chemistry can be almost tangible - as it was on Wednesday night when Leanne Benjamin and Jonathan Cope (replacing Bruce Sansom) gave a performance of searing intensity as the doomed lovers.

From their first encounter in the courtyard to the final scene in which she dies in his arms, Benjamin and Cope inject the choreography with a clarity and intelligence which makes you suspend disbelief. Cope is particularly suited to the role of Des Grieux, conveying all the strange tentativeness of his initial approach towards Manon, as well as the full force of his agony and sorrow at her death. Benjamin is a tiny figure, but hardly vulnerable, next to Cope, ideal for the ballet's perpetual man-handling which has Manon thrown, spun and dragged by Des Grieux and passed from client to client at the brothel.

The previous evening's performance, led by Sarah Wildor and Zoltn Solymosi, felt less satisfyingly cohesive. Wildor's Manon is fascinatingly voluptuous but too dreamy; Solymosi hurls himself into the work with great aplomb, but is also prone to lapse into lazy mannerism. As Lescaut, Manon's faithless, money-grabbing brother, Errol Pickford has found a role that exploits his sure technique and brings to the fore a powerful dramatic talent of which, in the past, there have only been hints.

Manon is not a ballet in which there is much opportunity for credible acting, simply because MacMillan's choreography frequently has the effect of turning the story's protagonists into caricatures. Even cameo parts are afflicted, the most laughable example being that of the Louisiana jailer who demands Manon's favours. Straddling her, he bends her leg to his crotch and then runs his hand along this "phallus" of Aubrey Beardsley proportions - at which point, the hardest thing to do is keep a straight face.

n To 11 Nov. Booking: 0171-304 4000