AFP

Melbourne, Jan 29: Switzerland's Roger Federer blasted Andy Roddick off-court in another fearsome display to reach the Australian Open final and stay on course for a record-tying 14th Grand Slam title on Thursday.

The second seed absorbed Roddick's serve and dominated the rallies to take it 6-2, 7-5, 7-5, with arch-rival Rafael Nadal playing Fernando Verdasco in the all-Spanish second semi-final on Friday.

Federer, now in his 18th Grand Slam final, has not lost any of his three previous Australian Open title matches and continues his unbeaten record against Roddick in Major tournaments.

"Andy's been playing really playing well so I knew I had a tough match ahead of me," Federer said.

"I thought I played really well tonight because Andy played good too, so it was fun."

Nadal is hot favourite for his semi with Verdasco, raising the prospect of a mouth-watering sixth Grand Slam final between the world's top two players and long-time rivals.

"People sort of forgot about him leading up to the Australian Open," Federer said of Nadal.

"But he's showing why he's the best player in the world. I would love to play him in the final, that's for sure."

It was demoralising for Roddick, who came into the match revitalised by a change in coach but got off to an appalling start and argued with the chair umpire as the first set slipped past in 32 minutes.

Federer had the seventh seed on a string and he reeled off 12 straight points to take the second, breaking for 6-5 and serving out with grim precision for the two-set lead.

Roddick tangled again with the umpire when he swore loudly and received a code violation, and was left staggered when Federer dug himself out of trouble with a brilliant drop shot, lob and stop-volley to hold for 5-5.

The American was then guilty of a howler as he patted the ball to Federer's feet with the court begging, gifting the crucial break point which the Swiss converted with an unstoppable forehand before calmly serving out the win.

Federer lost in the semis here last year and was beaten in the Roland Garros and Wimbledon finals by Nadal, who ended his record 237-week stint as world number one.

But he rescued his season by winning his fifth US Open title to move to 13 Grand Slam victories, one fewer than American great Pete Sampras.

Federer moves to 16-2 against Roddick, the former number one who won the 2003 US Open but has not reached a Grand Slam final since 2006.

He beat Andreas Seppi, Evgeny Korolev and 2005 champion Marat Safin in the early rounds before fighting back from two sets down against Tomas Berdych.

Federer then thrashed Argentina's Juan Martin del Potro in the quarter-finals, winning 6-3, 6-0, 6-0 in his most comprehensive victory in the last eight of a Grand Slam.

Federer also reached the semi-finals at the previous five Australian Opens, winning in 2004, 2006 and 2007, and last failed to make the last eight in 2003.

He can join Roy Emerson, Andre Agassi, Jack Crawford and Ken Rosewall as the only men to have won four or more titles here.

Roddick won against Bjorn Rehnquist, Xavier Malisse, Fabrice Santoro and Tommy Robredo to reach the quarter-finals, when defending champion Novak Djokovic retired with cramp in intense heat.