NEW HAVEN: Russian top seed Nikolay Davydenko was ousted from the final US Open tuneup event in a quarter-final here on Thursday, falling in three sets to sixth-seeded American Sam Querrey.

Querrey defeated Davydenko 6-3, 3-6, 6-4 to book a Friday semi-final berth against the winner of a later match between Frenchman Florent Serra and Jose Acasuso of Argentina at the 1.35 million-dollar ATP/WTA hardcourt tournament.

The defeat gives Davydenko the weekend off before Monday's start of the US Open, the year's final Grand Slam tournament. Davydenko, seeded eighth at Flushing Meadows, will play a qualifier in his first-round US Open match.

Russian seventh seed Igor Andreev also reached the New Haven semi-finals, defeating Argentina's Leonardo Mayer 6-4, 6-7 (4/7), 6-3. Andreev will next face either Austrian Jurgen Melzer or Spain's Fernando Verdasco.

On the women's side, Elena Vesnina reached the semi-finals with a 6-1, 7-5 triumph over Anna Chakvetadze in an all-Russian affair.