Fish unable to stop Roddick

Andy Roddick romped into the Australian Open semi-finals with a convincing 6-2 6-2 6-2 victory over former room-mate and fellow American Mardy Fish.

Fish upset fourth seed Ivan Ljubicic in the first round but failed to deal with the power of the sixth seed.

It took Roddick just one hour and 27 minutes to secure his third appearance in the last four of the Melbourne grand slam.

Roddick secured the first set with two breaks and despite dropping serve at the beginning of the second doubled his lead with three breaks of his own.

Two further breaks in the third set saw Roddick home to set up a semi-final meeting with number one seed Roger Federer.

Roddick powered past his compatriot with a 92% first-serve success rate, while Fish struggled throughout and conceded 26 unforced errors.