Roger Federer says Juan Martín del Potro was the better player, after losing to him 7-5, 3-6, 7-6 (8), 6-4 in the US Open in New York on Wednesday. The loss scuppered hopes for a semi-final showdown between Federer and Rafael Nadal, but the Swissman remarks that del Potro will have a better chance of beating Nadal than himself Mighty Juan Martín del Potro scuppers hopes of Federer-Nadal clash at US Open