Andy Roddick eased into the quarter-finals of the Artois Championships today when opponent Mardy Fish was forced to retire through injury.

Defending champion Roddick had just won the opening set of their third-round clash at Queen's Club in a tie-break when Fish called for the trainer.

The American had his left ankle heavily strapped but, after trying to stand on it, signalled he was unable to continue.

"Hopefully this will be just a two or three-day thing and he will be ready for Wimbledon," said Roddick, who will face British number one Andy Murray in the last eight after he beat Ernests Gulbis in three sets.