Top seed Juan Martin Del Potro, playing twice in one day for the first time in his career, reached the quarter-finals of the Washington Open with two straight-set triumphs.
Juan Martin Del Potro of Argentina serves against Ryan Harrison during the Citi Open at the William H.G. FitzGerald Tennis Center in Washington, DC, on August 1, 2013. Del Potro won 6-1, 7-5 in 70 minutes.
The 2009 US Open winner, a two-time Washington champion, on Thursday dispatched American Ryan Harrison 6-1, 7-5 in 70 minutes, then returned five hours later to eliminate Australian 14th seed Bernard Tomic 6-3, 6-3 in 69 minutes and advance at the combined ATP and WTA event.
"I feel good," Del Potro said. "I was training hard before I came here. During the night you feel much better. In the first match the sun was harder for me. In the night I move much better."
Despite double duty on his first match day since losing the longest semi-final in Wimbledon history to Novak Djokovic after four hours and 43 minutes, the 24-year-old Argentine advanced to a last-eight meeting with South Africa's 21st-ranked Kevin Anderson, who ousted American Mardy Fish 7-6 (7/2), 6-1.
"For the first day of the hardcourt season, I had a very good day," Del Potro said. "I beat two young players with good potential. I should play better all the matches."
Anderson, ranked 21st, broke Aussie James Duckworth in the only extra game he needed to win their rain-halted second-round match 6-3, 3-6, 6-4, and said he doubted world number seven Del Potro's double would have any impact.
"I would be very surprised if two matches today would affect him for a match tomorrow," Anderson said. "Somebody with the level of fitness of the players out here, it won't be a problem."
Del Potro has won all four prior matches with Anderson, the most recent last year at Basel.
"I will have to play better than today," Del Potro said. "Kevin is a very good server. I will have to find a way to return his serves. The court will help me. I like a fast court."
Del Potro fired six aces and 16 winners to beat Tomic, who committed 26 unforced errors, the last by netting a backhand on match point.
"I served really well," Del Potro said. "I played focused all the time."
Del Potro and Japanese second seed Kei Nishikori both had their second-round matches postponed Wednesday by rain with two other matches suspended by showers, but Nishikori -- ranked a career-best 11th -- could not pull off the double at the $1.76 million event.
After opening with a 7-5, 6-2 triumph over US wildcard Jack Sock, Nishikori was thrashed by 16th-seeded Cypriot Marcos Baghdatis 6-1, 6-2 in only 58 minutes.
Baghdatis booked a quarter-final berth against US eighth seed John Isner, who won last week in Atlanta and kept alive his hopes for back-to-back titles with a 7-5, 7-5 victory over Somdev Devvarman in their first meeting since Isner lost to the Indian in the 2007 US college final.
"I remember that match like it was yesterday," Isner said. "It was a very good win. Somdev is a very tough opponent. I'm happy to get through and move on."
Australian Marinko Matosevic withstood a 19-ace barrage to defeat Canada's Milos Raonic 7-5, 7-6 (9/7) and book a matchup with Russian Dimitry Tursunov, only the Aussie's fourth career ATP quarter-final.
"It was a big win for me," Matosevic said. "I'm on a good roll."
German third seed Tommy Haas won the last set of a rain-halted match to beat US qualifier Tim Smyczek 3-6, 7-5, 6-3, then faced Croatian 13th seed Ivan Dodig for a quarter-final berth against Bulgarian Gigor Dimitrov.
On the women's side, Russia's Olga Puchkova struck a ball in anger and wound up defaulting away the match with Argentina's Paula Ormaechea after the ball struck a line judge in the knee, sending him to the court writhing in pain.
"I'm very sorry that I accidently hit the line umpire in his knee," Puchkova said. "I wasn't looking where the tennis ball would go and I had apologized to the line umpire."