POERTSCHACH (Austria), May 25: Top seeds Nikolay Davydenko and Andy Roddick fell by the wayside in the quarter-finals of the Poertschach International on Thursday. Defending champion Davydenko, the top seed, struggled to keep pace with Argentina’s Juan Monaco and slumped to a 6-2, 6-7, 6-4 defeat. French youngster Gael Monfils upset American world number three Roddick 7-5, 6-3 to reach the semi-finals.

Following a sluggish start, Davydenko appeared to be back in control when he clinched the second set 7-5 in a tiebreak but could not sustain the momentum.

Monaco will next face Peru’s Luis Horna, a 7-6, 6-7, 6-1 winner over Albert Montanes.

Monfils, a wildcard entry at the Austrian event, will next face fourth seed Lleyton Hewitt after the Australian demolished Argentina’s Diego Hartfield 6-2, 6-2.

Second seed Roddick, looking to improve on his claycourt form, had appeared in total control after breaking his 20-year-old opponent to go 5-4 up in the first set.

Monfils broke back in style, however, levelling the scores with a great reaction volley at the net.

Another well-timed run to the net two games later helped the Parisian break Roddick a second time to complete an unlikely first set comeback.

Roddick had his own opportunity to fight back at the start of the second set when Monfils hit three successive forehands long to trail 0-40.

The Frenchman saved all three break points with an ace, a deft backhand volley and a perfectly-struck forehand winner, and was soon reapplying the pressure on Roddick, breaking the American once more to go 2-0 ahead.

Losing his cool in the Austrian heat, the 2003 US Open winner smashed his racket in the following game before hurling a string of abuse at himself. The outpouring had little effect though with Monfils holding his serve for the rest of the match to complete the win.

Hewitt was never in any danger of a similar upset during his match against Hartfield, breaking the world number 97 five times to set up his semi-final encounter with Monfils.

The Australian, who reached the last four in Hamburg last week, has now made it to two successive clay-court semis after a previous three-year drought.

Results (X denotes seeding):

Quarter-finals:

Lleyton Hewitt (AUS x4) bt Diego Hartfield (ARG) 6-2, 6-2; Luis Horna, (PER) bt Albert Montanes (ESP) 7-6 (4), 6-7 (2), 6-1; Gael Monfils (FRA) bt Andy Roddick (US x2) 7-5, 6-3; Juan Monaco (ARG) bt Nikolay Davydenko (RUS x1) (1) 6-2, 6-7 (5), 6-4.