Washington - Top seed Juan Martin Del Potro has advanced with ease Thursday at the ATP and WTA Citi Open while Olga Puchkova fired a ball at a line judge and was defaulted.
Rain on Wednesday postponed the opening matches for Del Potro and Japanese second seed Kei Nishikori, who had first-round byes, and halted two other men's matches at the $1.76 million hardcourt event.
So facing two matches on Thursday, Del Potro made the most of his time on the court, ripping American Ryan Harrison 6-1, 7-5 in 70 minutes in his first start since losing to top-ranked Novak Djokovic in an epic five-setter, the longest semi-final in Wimbledon history.
"It's going to be my first time to play two matches in one day, but I think I will be ready," said the Argentine.
Del Potro, who showed no signs of a knee injury that nagged him at Wimbledon, booked a third-round date against Australian 14th seed Bernard Tomic.
"I expect a tough match," Del Potro said.
"Tomic has a lot of talent and he is going to be a great player very soon."
Del Potro broke Harrison twice to open the match, winning 16 of the first 22 points on his way to a 4-0 lead and broke again to claim the first set in 22 minutes.
Del Potro, a two-time Washington winner and the 2009 US Open champion, did not break again until the final game.
"I played well in the first set and it got humid," Del Potro said.
"The sun came out and it was difficult to play. Now I have to recover."
Nishikori, ranked a career-best 11th in the world, defeated American Jack Sock 7-5, 6-2 in one hour and 44 minutes to book a third-round match later with Cypriot Marcos Baghdatis.
"If you're in good shape, maybe it helps to get out there and get going," Harrison said.
On the women's side, the only match halted Wednesday was Puchkova's.
She trailed Argentina's Paula Ormaechea 3-6, 6-3, 2-1 when play resumed Thursday but surrendered a break and trailed 4-1 in the final set.
Upset at herself after a point, Puchkova struck a ball in frustration and it slammed into the knee of a line judge, injuring the man and prompting the umpire to default the match to her South American foe.
"It's not my favourite way to win a match," Omachea said in a Twitter posting.
Puchkova, who had not deliberately fired the ball at the official, walked over to see the line judge as he lay on the court after being struck and apologized to him.
Ormaechea wll next face Germany's Andrea Petkovic, the only woman to reach the third round Wednesday.
South African seventh seed Kevin Anderson, coming off a runner-up finish last week in Atlanta, broke Australian James Duckworth in the last game of a rain-halted match once play resumed to complete a 6-3, 3-6, 6-4 triumph.
"It was definitely tricky coming out very near the conclusion of the match," Anderson said. "I did quite well in the game I played. It was just like a warmup."
Anderson was set to face American Mardy Fish later to decide a quarter-final spot.
Fish, making a comeback after missing much of the past year with heart problems, took his first two wins since March earlier this week and has won both prior matches against Anderson.
The winner puts himself in Del Potro's path for a potential Friday quarter-final, but Anderson does not expect the South American star to be slowed even after two matches in one day.
"It's definitely tough. It's never easy," Anderson said.
"Depends on the length of the matches. Del Potro as an example, I would be very surprised if two matches today would affect him for a match tomorrow.
"Somebody with the level of fitness of the players out here, it won't be a problem."
German third seed Tommy Haas won the other rain-halted match, beating US qualifier Tim Smyczek 3-6, 7-5, 6-3.
Results on Thursday from the fourth day of the ATP and WTA Citi Open (x denotes seed):
Kevin Anderson (RSA x7) bt James Duckworth (AUS) 6-3, 3-6, 6-4
Juan Martin del Potro (ARG x1) bt Ryan Harrison (USA) 6-1, 7-5
Kei Nishikori (JPN x2) bt Jack Sock (USA) 7-5, 6-2
Tommy Haas (GER x3) bt Tim Smyczek (USA) 3-6, 7-5, 6-3
Paula Ormaechea (ARG) bt Olga Puchkova (RUS) 3-6, 6-3, 4-1 -- default
Ekaterina Makarova (RUS x3) bt Caroline Garcia (FRA) 6-2, 6-0
Alize Cornet (FRA x4) bt Heather Watson (GBR) 6-4, 6-4