LAS VEGAS, March 3: Just over eight hours after he found out that he'd be playing in the quarter-finals on Friday, Evgeny Korolev advanced to the semi-finals in the Tennis Channel Open with a 6-4, 6-4 victory over fellow 19-year-old Sam Querrey.

Korolev, from Russia, got back into the event when the ATP Tour reversed its decision to give top-seeded James Blake the controversial quarter-final spot.

Blake, the 2006 winner, led Juan Martin del Potro 6-1, 3-1 on Thursday in round-robin play when del Potro retired because of respiratory distress.

Korolev, a 6-2, 6-4 winner over Blake in their opening-round match on Tuesday, initially was declared the group winner based on his completed victory, but the tour reversed that decision on Thursday night before switching back to Korolev on Friday.

“Everyone does mistakes,” Korolev said. “But it's really not fair to me or James. I was told I was playing when I got a call at 5am from my agent and at 6am from the (ATP Tour) supervisor I tried to concentrate and fight for every ball. I thought if I lose, guys will think they made the wrong decision.”

Korolev said he went to sleep at 3am because he thought that he was out of the tournament. Then, his sleep was interrupted by phone calls before he got back to sleep and awakened at 9am for the noon match.

Korolev will face fourth-seeded Jurgen Melzer in the semi-finals. The Austrian beat Jan Hernych of the Czech Republic 6-3, 3-6, 6-3.

In the other quarter-finals, second-seeded Lleyton Hewitt of Australia beat Spain's Feliciano Lopez 6-3, 6-2, and third-seeded Marat Safin of Russia edged Spain's Fernando Verdasco 6-1, 6-4.

Hewitt had five aces in each set and won 24 of 27 first-serve points. He also saved all four break points he faced.

The world's former No.1 ranked player has only won two tournaments since January 2005. He lost to Blake in last year's final. Hewitt won the event in 2000 and 2003 when it was played in Scottsdale, Ariz.

Results (x denotes seeding):

Singles

Men (quarter-finals): Evgeny Korolev (RUS) bt Sam Querrey (US) 6-4, 6-4; Marat Safin (RUS x3) bt Fernando Verdasco (ESP x5) 6-1, 6-4; Jurgen Melzer (AUT x4) bt Jan Hernych (CZE) 6-3, 3-6, 6-3; Lleyton Hewitt (AUS x2) bt Feliciano Lopez (ESP) 6-3, 6-2.

Women (quarter-finals): Akiko Morigami (JAP x1) bt Alberta Brianti (ITA x6) 6-3, 6-4; Jarmila Gajdosova (SLV x7) bt Tatiana Poutchek (BER) 6-4, 6-3; Caroline Wozniacki (DEN) bt Bettina Jozami (ARG) 6-1, 6-0; Julia Vakulenko (UKR x4) bt Varvara Lepchenko (UZB x8) 6-0, 6-1.

Doubles

Men (quarter-finals): Ramon Delgado (PAR) and Gustavo Kuerten, (BRA) bt Frantisek Cermak and Jaroslav Levinsky (CZE x4) 6-2, 6-2; Bob and Mike Bryan (US x1) bt Chris Haggard (RSA) and Bjorn Phau (GER) 6-1, 6-4.

Women (semi-finals): Maret Ani, Estonia, and Alberta Brianti (ITA) bt Kristina Barrois and Tatiana Malek (GER) 6-4, 2-6, 7-5; Viktoria Azarenka and Tatiana Poutchek (BER x4) bt Jarmila Gajdosova, (SLV) and Akiko Morigami (JAP x1) 7-6 (4), 6-4.

MOYA SHOCKS FERRERO IN SEMIS

ACAPULCO, (Mexico): Former world No. 1 Carlos Moya shocked top-seeded Juan Carlos Ferrero on Friday to reach the men's final of the WTA and ATP Mexico Open clay court tournament.

The eighth-seeded Spaniard beat his compatriot 2-6, 6-2, 6-3 to give himself a chance at a third Acapulco title, to go with those he won in 2002 and 2004.

In the final he will face Argentina’s fourth seed Juan Ignacio Chela, who was trailing second-seeded compatriot Agustin Calleri when Calleri was felled by a hamstring injury.

Calleri appeared poised to reach his second Acapulco final when he took a 6-4, 5-3 lead.

As Chela served to save the match, Calleri injured his right hamstring. He received treatment at the time and again at the changeover, but after he was unable to serve out the match at 5-4, Calleri retired.

Italy's Flavia Penetta and France's Emilie Loit booked their places in the women's final. Penetta, the fifth seed, defeated compatriot Sara Errani 6-2, 6-4.

Loit battled back after dropping the first set 0-6, finally downing Germany's Julia Schruff 0-6, 6-2, 6-1. For Schruff it was the end of a week that included a second-round upset of top seed Marion Bartoli of France.

Results:

Singles

Men (semi-finals): Juan Ignacio Chela (ARG x4) bt Agustin Calleri (ARG x2) 4-6, 5-5, retired; Carlos Moya (ESP x8) bt Juan Carlos Ferrero (ESP x1) 2-6, 6-2, 6-3.

Women (semi-finals): Emilie Loit (FRA) bt Julia Schruff (GER) 0-6, 6-2, 6-1; Flavia Pennetta (ITA x5) bt Sara Errani (ITA) 6-2, 6-4.

Doubles

Men (semi-finals): Lukas Dlouhy and Pavel Vizner (CZE x1) bt Jordan Kerr (AUS) and David Skoch (CZE) 3-6, 6-2, 10-7 tiebreak.

Women (semi-finals): Lourdes Dominguez Lino and Arantxa Parra Santonja (ESP) bt Eva Birnerova and Barbora Zahlavova Strycova, (CZE) 3-6, 6-4, 10-6 tiebreak; Emilie Loit (FRA) and Nicole Pratt (AUS x2) bt Flavia Pennetta and Roberta Vinci (ITA x3) 6-2, 2-6, 10-6 tiebreak. –Agencies