RAFA Nadal lost his first 'round robin' match of the London Masters in the O2 stadium today.

The Mallorca-born world number two took to the court for the first time today against Swede Robin Söderling, who stepped in at the last minute to replace an injured Andy Roddick.

Nadal holds a 3-1 head to head record against the Swedish player, with his only defeat coming at this year's Roland Garros, but today he was unable to avenge the defeat in Paris.

Although Nadal played 'aggressively and energetically', serving well and making only 24 errors compared to Söderling's 27, the latter took advantage of his first match point to finish the encounter 6-4, 6-4 in 40 minutes.

Nadal's next rival, on Wednesday, will be the loser of this evening's group match between Novak Djokovic and Nikolay Davydenko.

Yesterday evening, Fernando Verdasco was up against world number one, Roger Federer in the other round robin group.  Some breathtaking tennis with passing shots of pinpoint accuracy allowed him to take the first set against the Swiss player 6-4, but when Federer took the second set 7-5, Verdasco's head dropped and Federer got into his stride, taking the final set easily 6-1.

Verdasco's next match is against Argentinian Juan Martín del Potro tomorrow lunchtime.