Roger Federer (1) vs. Nikolay Davydenko (2), 1-1

Kirilenko needed less than 90 minutes to down the unseeded Czech in straight sets, 6-4, 6-2, on the red dirt at Estadio Nacional.

It was the first singles title of the year for the 21-year-old Kirilenko and the third of her career.

Nicolas Almagro (5) leads David Ferrer (1), 2-1

Maria Kirilenko (2) def. Iveta Benesova, 6-4, 6-2

Blake made relatively quick work of eighth-seeded Spaniard Oscar Hernandez, 6-3, 7-6 (7-3) at River Oaks Country Club on Saturday and will now pursue his first clay-court championship.

The 28-year-old Blake has claimed 10 singles title during his career, but has yet to experience success on this surface.

The fifth-seeded Williams disposed of unseeded French upstart Alize Cornet 7-5, 6-3 on the green clay at Family Circle Tennis Center. Williams, the 2003 Charleston runner-up, reached the semis with a 7-5, 4-6, 6-1 win over Russian Maria Sharapova in Friday's quarterfinal match.

Williams was the champion at the so-called "Fifth Major" in Miami just two weeks ago.

James Blake (1) vs. Oscar Hernandez (8) Wayne Odesnik leads Marcel Granollers-Pujol (7), 6-3

The Swiss superstar Federer dropped the first set, then handled German Denis Gremelmayr 2-6, 7-5, 6-1 on the red clay at Estadio Nacional. The 12- time Grand Slam champion Federer is still seeking his first trip to a final this year. Federer is now 2-0 lifetime against Gremelmayr, with the previous victory coming on a hardcourt in Thailand three years ago.

The red-hot world No. 4 Davydenko, seeded second in Portugal, disposed of Frenchman Florent Serra 6-2, 6-2 to win his 11th straight match. The gritty Russian titled in Miami two weeks ago to secure his second career Masters Series shield.

Elena Dementieva (4) vs. Vera Zvonareva (9) Alize Cornet leads Serena Williams (5), 1-0

Roger Federer (1) leads Denis Gremelmayr, 2-6, 7-5, 4-0 Nikolay Davydenko (2) vs. Florent Serra

Maria Kirilenko (2) def. Klara Zakopalova (6), 2-6, 6-3, 7-5 Iveta Benesova def. Maret Ani, 6-2, 6-1

David Ferrer (1) leads Tommy Robredo (3), 2-6, 6-2, 5-3 Nicolas Almagro (5) vs. Evgeny Korolev

The fifth-seeded Williams improved to 5-2 lifetime against the second-seeded Sharapova with a 7-5, 4-6, 6-1 decision on the green clay at Family Circle Tennis Center. Later action saw another upset, as Russian Vera Zvonareva knocked off top-seeded Jelena Jankovic, 6-2, 3-6, 6-2.

Jankovic, a native of Serbia, won last year's event by defeating another Russian, Dinara Safina, in the finale, but dropped the first set to Zvonareva and couldn't win after rallying to take the second set.

Blake topped fifth-seeded Argentine Agustin Calleri, 6-4, 6-3 at River Oaks Country Club. This is Blake's second career semifinal berth in Houston, as he fell to Argentine Mariano Zabaleta last year.

Fish, the third seed, lost to eighth-seeded Spaniard Oscar Hernandez, 6-2, 7-6 (7-5). The world No. 42 Fish was bidding for his second title in Houston, having lifted the trophy in 2006.

Roger Federer (1) leads Frederico Gil, 6-4, 1-1 Nikolay Davydenko (2) vs. Marc Gicquel (7) Denis Gremelmayr vs. Jiri Vanek Flavio Cipolla vs. Florent Serra

Maria Kirilenko (2) vs. Tathiana Garbin (5) Klara Zakopalova (6) leads Karin Knapp (3), 3-2 Iveta Benesova leads Camille Pin (8), 3-6, 6-2, 1-0 Maret Ani leads Olga Savchuk, 6-5

Jelena Jankovic (1) vs. Vera Zvonareva (9) Maria Sharapova (2) vs. Serena Williams (5) Elena Dementieva (4) vs. Patty Schnyder (7) Agnes Szavay (10) vs. Alize Cornet

James Blake (1) vs. Agustin Calleri (5) Mardy Fish (3) vs. Oscar Hernandez (8) Marcel Granollers-Pujol (7) vs. Marcos Daniel Wayne Odesnik vs. Sergio Roitman

David Ferrer (1) vs. Fernando Verdasco (7) Juan Monaco (2) vs. Nicolas Almagro (5) Tommy Robredo (3) def. Potito Starace (8), 6-3, 3-0, retired Evgeny Korolev vs. Robin Haase

Blake disposed of Harrison 6-3, 6-2 at River Oaks Country Club. Also, fifth- seeded Argentine Agustin Calleri cruised past Chilean Paul Capdeville 6-2, 6-1. Brazilian Marcos Daniel took out dual-Olympic gold medalist Nicolas Massu 7-6 (7-3), 6-2, while Argentine Sergio Roitman erased Russian Igor Kunitsyn 6-3, 7-6 (7-3). Massu was the Houston runner-up in 2000.

In other second-round play, American Wayne Odesnik ousted sixth-seeded Israeli Dudi Sela 6-3, 7-5 and seventh-seeded Spaniard Marcel Granollers-Pujol handled Aussie Peter Luczak 6-3, 6-2.

Blake disposed of Harrison 6-3, 6-2 at River Oaks Country Club. Also, fifth- seeded Argentine Agustin Calleri cruised past Chilean Paul Capdeville 6-2, 6-1. Brazilian Marcos Daniel took out dual-Olympic gold medalist Nicolas Massu 7-6 (7-3), 6-2, while Argentine Sergio Roitman erased Russian Igor Kunitsyn 6-3, 7-6 (7-3). Massu was the Houston runner-up in 2000.

In other second-round play, American Wayne Odesnik ousted sixth-seeded Israeli Dudi Sela 6-3, 7-5 and seventh-seeded Spaniard Marcel Granollers-Pujol handled Aussie Peter Luczak 6-3, 6-2.

The second-seeded and former top-ranked Sharapova got past Ukrainian Tatiana Perebiynis 7-5, 6-2 in 1 1/2 hours on the green clay at Family Circle Tennis Center. Sharapova and Williams will do battle here in a blockbuster quarterfinal on Friday.

Williams is 4-2 lifetime against Sharapova, including wins over the Russian in their last three meetings. The two superstars have never met on clay.

James Blake (1) vs. Ryan Harrison Agustin Calleri (5) vs. Paul Capdeville Wayne Odesnik def. Dudi Sela (6), 6-3, 7-5 Marcel Granollers-Pujol (7) def. Peter Luczak, 6-3, 6-2 Marcos Daniel leads Nicolas Massu, 7-6 (7-3), 0-1 Sergio Roitman leads Igor Kunitsyn, 6-3, 2-4

The top-seeded Ferrer blew past qualifier and fellow Spaniard Pablo Andujar 6-3, 6-4, while a fifth-seeded Almagro won his 12th straight match at this clay-court event by dismissing Argentine Eduardo Schwank 6-3, 6-4 at CT Valencia. Almagro is the two-time defending Valencia titlist, having beaten Italian Potito Starace in last year's finale. Ferrer was the runner-up here back in 2005.

Meanwhile, second-seeded Argentine Juan Monaco handled Spaniard Guillermo Garcia-Lopez 6-4, 6-4 and seventh-seeded Spaniard Fernando Verdasco vaulted past German Mischa Zverev 6-4, 6-2.

Jelena Jankovic (1) vs. Anastasia Rodionova Maria Sharapova (2) vs. Tatiana Perebiynis Elena Dementieva (4) vs. Victoria Azarenka (13) Serena Williams (5) vs. Katarina Srebotnik (12) Vera Zvonareva (9) leads Marion Bartoli (6), 6-4, 4-5 Patty Schnyder (7) vs. Agnieszka Radwanska (11) Agnes Szavay (10) leads Dinara Safina (8), 6-2, 5-4 Alize Cornet leads Sorana Cirstea, 6-1