Top-ranked Serena Williams came from a set and 5-2 down to beat Avarane Rezai 3-6, 7-5, 6-4 Thursday and move into a Sydney International final against defending champion Elena Dementieva. Rezai was serving for the match at 5-3 in the second set but reigning Australian Open champion Serena won the next five games to level it and go a break up in the third. Rezai of France recovered breaks in the first and seventh games of the third set but Serena broke her to lead 5-4 and then served it out. “Was I down that far? I didn't even realize,” Serena said. “I don't think she lost her way at all. I felt like I literally lifted my game.” Serena, winner of 11 Grand Slam singles titles, will play Friday against Olympic champion Dementieva, who beat sixth-seeded Victoria Azarenka of Belarus 6-3, 6-1. In men's quarterfinals, Richard Gasquet of France had a 6-3, 7-6 (7) win over Italian Potito Starace and Frenchman Julien Benneteau beat Argentina's Leonardo Mayer 6-4, 6-7 (5), 6-0. Former Australian Open finalist Marcos Baghdatis beat former No. 1 Lleyton Hewitt 4-6, 6-2, 6-3, ending Hewitt's attempt for his fifth Sydney title. Baghdatis, ranked 42, will face American Mardy Fish, who won the night quarterfinal against Australian Davis Cup member Peter Luczak, 7-6 (7/5), 6-2. Isner beats Robredo In Auckland, American John Isner completed the elimination of Spain's top four seeds from the Heineken Tennis Open with a 7-6 (5), 3-6, 6-4 quarterfinal win over top-seeded Tommy Robredo Thursday. Spain supplied five of the eight seeded players for the tournament but only eighth-seeded Albert Montanes, who beat Swiss qualifier Michael Lammer 6-3, 6-3, made it past the quarterfinals. Second seeded David Ferrer and fourth seeded Nicolas Almagro were beaten in Wednesday's second round while third-seeded Juan Carlos Ferrero was forced to retire in the second round with an ankle injury. Robredo appeared on course for the semifinals when he led 3-1 in the deciding set but the big-hitting Isner clawed back a service break, then claimed the match with a second break in the 10th game. Isner's win saw him improve on last year's quarterfinal exit in Auckland, when he reached the main draw through qualifying, and to avenge his narrow, three-set loss to Robredo while representing the United States at last week's Hopman Cup. Isner's semifinal opponent will be Montanes, who was efficient in beating Lammer in 1 hour, 15 minutes. Montanes gained the only break of the first set in the sixth game for a 4-2 lead and broke Lammers in the first and last games of the second. Wild card Arnaud Clement, whose second round ended near midnight Wednesday, returned to center court hours later to beat sixth-seeded Jurgen Melzer 6-2, 7-5. His semifinal opponent will be fifth-seeded and former champion Philipp Kohschreiber, who beat Marc Gicquel of France 6-3, 6-1.