French top seed Gael Monfils won two matches in 10 hours on Thursday, ousting Russian Dmitry Tursunov 6-2, 7-6 (11/9) in the latter to reach the quarter-finals of the $1.4 million ATP Washington Classic.
Seventh-ranked Monfils, a French Open quarter-finalist, had earlier fired 17 aces in downing American Ryan Sweeting 6-3, 7-6 (7/3), his twice-in-a-day feat of endurance necessitated by rain Wednesday that postponed six matches.
Monfils must win five matches in four days here to claim his fourth career ATP crown after titles last year at Montpelier, in 2009 at Metz and in 2005 at Sopot. His only outdoor hardcourt final since 2006 was last year at Tokyo.
Serbian sixth seed Janko Tipsarevic, the next foe for Monfils, and Cypriot seventh seed Marcos Baghdatis, who went six sets in one day for the first time, also won twice Thursday to book last-eight berths at the US Open tuneup event.
"It's good to finish six sets and physical-wise I feel good," Baghdatis said. "You know you can do it, but it's nice to achieve that."
World No. 45 Tursunov, who won his seventh career ATP title last month at Rosmalen, was denied on all three break chances against Monfils in the first set, which took only 33 minutes.
Tursunov, who dropped his only prior meeting with Monfils in 2006 at Doha, broke Monfils to level the second set 2-2 and they battled to a tie-break, which was deadlocked at 5-5.
Monfils squandered three match points, sending two forehands and a backhand beyond the baseline. Turnsunov hit a backhand long on his only set point and Monfils took the match two points later when the Russian sent a forehand wide.
In his opener, Monfils connected on 71 percent of his first serves and dazzled 66th-ranked Sweeting, who at times could only marvel at the moves of the lanky Frenchman, who hit shots behind-the-back and after astonishing leaps.
"He's just so athletic. I was laughing because it was so amazing," Sweeting said. "Sometimes I respected his speed too much, but the main factor was how well he served. He was placing it really well. It was pretty tough to read."
Monfils, 24, split with Australian coach Roger Rasheed after Wimbledon and came only with fitness coach Patrick Chamagne to Washington, where he reached the semi-finals in 2007 in his only prior appearance.
"I had been unhappy," Monfils said, adding that with Chamagne alone for now "I think I'm happy with that."
Tipsarevic, 27, ousted Germany's Michael Berrer 6-3, 6-4, in the afternoon and dispatched Bulgaria's Grigor Dimitrov 6-4, 6-2 in the nightcap to book a date with the Frenchman in Friday's last quarter-final.
Reigning Commonwealth Games and Asian Games champion Somdev Devvarman fell to Baghdatis 6-2, 0-6, 7-5 in a second-round match. Baghdatis later outlasted Brazil's Tomaz Bellucci 3-6, 6-3, 6-2 to reach the quarter-finals.
Baghdatis managed only eight points in the second set against Devvarman, but battled back in the last, breaking in the 11th game and denying the Indian on two break points in holding for the match.
"It was just a dogfight. He played well to close out the match," Devvarman said. "I'm playing well. I'm not going to be an easy guy to beat the next few matches. If I can use my athleticism to be more aggressive, that will help."
Baghdatis, last year's Washington runner-up, will next face Donald Young, a 22-year-old American who beat compatriot Michael Russell 6-3, 6-3, avenging a loss two weeks ago at Atlanta to reach only his second ATP quarter-final, the first since 2008 at Memphis.
Spanish fifth seed Fernando Verdasco snapped a four-match losing streak to Russian Nikolay Davydenko with a 6-4, 7-5 triumph. Verdasco next faces Czech Radek Stepanek, who beat Finland's Jarkko Nieminen 6-4, 3-6, 6-2.
John Isner outlasted pal and neighbor James Blake 7-6 (7/0), 1-6, 7-6 (7/4) in an all-American third-round match.
Isner, trying to reach his third final in a row after winning at Newport and losing to Mardy Fish at Atlanta, will next face Serbian third seed Viktor Troicki, who eliminated South Africa's Kevin Anderson 6-3, 6-3.