Roddick to face compatriot Isner in semi-finals

Isner beat Czech eighth seed Tomas Berdych 6-3, 6-7 (10-12), 6-2 here Friday night.
The semi-finals in the American capital will feature a bill which also includes an all-South American clash between fourth seed Fernando Gonzalez and defending champion Juan Del Potro of Argentina.

Del Potro got a free ride as Swedish opponent Robin Soderling withdrew before their match with a lingering right elbow injury.
Roddick is seeking redemption as he returns to tennis for the first time in five weeks after losing a third Wimbledon final to Roger Federer.
Fourth seed Fernando Gonzalez had to work for his hard-hitting win, firing 18 forehand winners to overwhelm German tenth seed Tommy Haas 7-5, 6-4.
The veteran Chilean, who took four weeks off after a poor Wimbledon to rest a knee plagued with the same patella tendon problem that afflicts Rafael Nadal, showed no signs of rust as he moved into a semi-final against his fellow South American Del Potro.
The Chilean leads the Argentine, winning all three of their previous matches, the last at the Australian Open in 2007.
"I barely hit a ball when I was at home," said Gonzalez, who said that the change of surface from clay to grass two months ago gave him more pain in his knee.
"I was also scared of the hot weather here," added the player who came out of the southern winter only to find unseasonably mild temperatures. "Tommy and I both played good tennis at the start, but I was able to get a break in the first set.
"In the second he gave me two break points and I took them."
But it was not all one-way traffic for the number 11 who stands 27-7 on the season. Serving for victory leading a set and 5-2, Gonzalez lost serve to give Haas some breathing space.
After the 31-year-old German held, Gonzalez finally put the victory away a game later on his second match point as he smashed home the win in just under 90 minutes.
Del Potro was glad to have a free afternoon after the pullout of Soderling, elongating his practice to an hour and planning to relax for the rest of the day.
"I found about the pullout during my warm-up so I just extended the session," said the world number six South American. "I need time anyway to rest for my next match.
"The courts are playing a lot faster this year and we players can all feel the difference."
French Open finalist Soderling said he has been feeling his elbow for several weeks. "I've just over-played," said the man who knocked Nadal out of that major on May 31 in the fourth round and lost the final to Roger Federer.
"I took a week off after Hamburg (July) but it is still bothering me, I hope to be ready for the US Open."

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