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.
"I'm in good shape," Monfils said. "I come from the clay season so I'm used to having long 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 of the match's 99 minutes.
Tursunov broke Monfils to level the second set 2-2 and they battled to a tie-break.
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.
"For sure it's better for the next match for the recovery" not to go three sets," Monfils said. "I can handle six sets in a day so it's OK for me."
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 has made fitness coach Patrick Chamagne his overall coach.
"We both wanted different goals," Monfils said of Rasheed. "Now (Chamagne) is the main coach. I think he can handle it. I can trust in him."
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.
Monfils, a 2007 semi-finalist in his only prior Washington event, is 3-2 lifetime against the Serb, winning their past two meetings in last year's US Open third round and the Davis Cup finals.
"It was more pressure when we played there and in the US Open it was very tough," Monfils said. "I'll try to be aggressive, make him make mistakes."
Baghdatis, last year's Washington runner-up, defeated reigning Commonwealth Games and Asian Games champion Somdev Devvarman 6-2, 0-6, 7-5 and later outlasted Brazil's Tomaz Bellucci 3-6, 6-3, 6-2.
Baghdatis 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).
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.