Melbourne: World number one Lleyton Hewitt dished out a merciless straight sets thrashing to his Australian compatriot Todd Larkham in a second round match at the Australian Open on Thursday.

Hewitt savaged the 235-ranked Larkham 6-1, 6-0, 6-1 in a blistering 74 minutes on Rod Laver Arena centre court.

The Australian dynamo set up a third round meeting with the Czech Republic's Radek Stepanek.

Hewitt ripped through qualifier Larkham's serve, breaking it eight times in a match that never was a contest.

Hewitt is bidding to become the first homegrown winner of the Australian Open in 27 years.

The top seed's cakewalk was in stark contrast to his desperate fight to beat Swedish qualifier Magnus Larsson over three hours and five sets in Tuesday's first round.

It was a sad finish for the out-gunned Larkham, who served a double-fault on match point to hand the match to Hewitt.

He was troubled by cramps throughout the match and was given the runaround by Hewitt and needed to regain his breath several times after being pushed around the court by the world number one.

"I hit the ball really well tonight and I was confident right from the start," Hewitt said moments after the win.

"I've got to give Todd a lot of credit. He won three matches in qualifying to get in the main draw and it was a huge step up for him tonight.

"I had to handle it very well mentally which I did."

Agencies