Tennis: World number one Roger Federer was forced to dig deep to keep his perfect record in Masters Cup round-robin matches intact with a 4-6, 7-6, 6-4 win over a fired-up Andy Roddick yesterday.

American Roddick hassled and hustled Federer out of his comfort zone to win the first set and then had three match- points in a thrilling tiebreak in the second, which the Swiss came back from 4-1 down to win 10-8.

Federer won the Masters Cup in 2003 and 2004, was losing finalist last year and has still not lost in 14 group matches at the tournament.