Austrian Stefan Koubek, who won the Delray Beach International title in 2000, took out eighth-seeded Lu Yen-hsun of Taiwan 6-4, 6-3 in a late match on Wednesday.
“I’m moving pretty well,” said Koubek, who had spinal surgery in May. “I have good feeling on this court. I can go for my shots even if it’s windy.”
Lu was unable to reproduce the form that a day earlier had propelled him to a first-round victory over former world no. 1 Lleyton Hewitt of Australia.
The 59th-ranked Lu now has a 4-4 record in ATP matches this year.
Meanwhile Christophe Rochus of Belgium upset second-seeded American Sam Querrey 6-4, 6-1 on Wednesday.
“I played good, he played bad,” Rochus said. “He wasn’t serving big and when I played fast, he was in trouble.”
The 60th-ranked Rochus played a smart game to challenge the taller Querrey, who midway through the match wandered around the court.
“He played well, he comes up with good shots,” Querrey said. “He comes to the net. He has those cocky, arrogant backhand drop shots, it’s annoying.”
The 34th-ranked Querrey started the match with a 3-1 lead, but his serve, usually solid, was unreliable all night.
Querrey had an overall first serve rate of 49 percent and was at 38 percent on first serve in the first set.
Rochus, who also made the quarter-finals at Memphis, used a crafty mix of shot-making to prevent Querrey from finding any rhythm in the match.
Querrey led 3-1 in the match, but Rochus went on to win 11 of the next 13 games.
Five of the eight seeds have already been eliminated: Querrey, Lu, third-seeded Ernests Gulbis, fifth-seeded Steve Darcis and fourth-seeded Igor Kunitsyn.
Earlier, qualifier Evgeny Korolev of Russia defeated American Robert Kendrick 3-6, 6-3, 7-5 to move into today’s quarter-finals.
Korolev was due to play 83rd-ranked Guillermo Garcia-Lopez of Spain in the last eight.
The Spaniard rallied for a 5-7, 6-3, 6-3 win over the 79th-ranked Gilles Muller of Luxembourg.
Additional reporting by staff writer
AP, DUBAI, UNITED ARAB EMIRATES
Novak Djokovic and Andy Murray led the top six seeds into the quarter-finals of the Dubai Championships on Wednesday.
Top-seeded Djokovic had to fight back from a break down in the last set to beat Jan Hernych of Czech Republic 6-3, 3-6, 6-4 over more than two hours, while second-seeded Murray cruised past Arnaud Clement of France 6-2, 6-3.
Djokovic, yet to reach a final this year, will next play fifth-seeded Marin Cilic, who already has two titles this season in Chennai and Zagreb. Cilic overcame Julien Benneteau of France 6-3, 4-6, 7-5 in his second straight three-setter.
Next up for Murray will be unseeded Richard Gasquet of France, who took more than three hours to edge Simone Bolelli of Italy 6-7 (4), 6-3, 7-6 (5).
Third-seeded Gilles Simon of France dispatched Teimuraz Gabashvili of Russia 6-1, 6-2 to set up a quarter-final with countryman Fabrice Santoro, who beat qualifier Marco Chiudinelli of Switzerland 3-6, 6-1, 7-6 (1).
The other quarter-final pits fourth-seeded David Ferrer against sixth-seeded Igor Andreev.
Spain’s Ferrer beat Germany’s Philipp Kohlschreiber 6-4, 6-2, and Andreev topped fellow Russian Dmitry Tursunov 5-7, 6-4, 6-3.
AP, ACAPULCO, MEXICO
Defending champion Nicolas Almagro endured more than two-and-a-half hours on clay to reach the Mexican Open quarter-finals, but two-time winner Carlos Moya lost in the second round on Wednesday.