Hamstring injury forces Roddick out of Aussie Open

Andy Roddick has an injured hamstring that forced him to retire from his match against Lleyton Hewitt at the Australian Open.

Australian wild-card entry Hewitt was leading the match between two former No. 1-ranked players 3-6, 6-3, 6-4 Thursday night when Roddick called for the doctor and trainer in the break after the third set.

Roddick had fallen to the court early in the second set, but played despite being in obvious pain from the leg injury.

Hewitt, who has won two major titles and was a finalist here in 2005, will play Canada's Milos Raonic in the third round.