Andy Roddick's swift and stealthy progress through the Australian Open has continued after Russian Nikolay Davydenko failed to last the distance in their quarter-final.

The No.26 seed withdrew with breathing problems when trailing 6-3 7-5 4-1.

Roddick has spent just seven hours and 42 minutes on court in his first five matches at the Australian Open, only half the time of his two potential semi-final opponents.

"Not quite as dramatic as I normally am I guess," was the second-seeded Roddick's summation of his run this year at Melbourne Park.

"It's been pretty smooth sailing, in as much as I've ever had being in this position in a grand slam.

"But at the same time, that could end up being a good thing because I don't have too many miles on me so far in this tournament."

The contrast with his only other appearance in the last four at Melbourne Park two years was stark.

On that occasion he was out on his feet after beating Younes El Aynaoui in their classic five-hour quarter-final and was easy prey in the semis for Rainer Schuettler.

Davydenko had advanced to his first-ever grand slam quarter-final with a straight-sets win over Guillermo Canas, but admitted afterwards that the shortness of breath would probably have forced him out of that match if it had gone to a fourth set.

The problem became too much to handle on another stinking hot day in Melbourne.

Brought to you by AAP © 2024 AAP