* Serena's first loss since opening round at French Open
* Venus edges U.S. Open champion Stosur in three sets
(Adds Serena quotes)
By Simon Evans
MASON, Ohio, Aug 17 Olympic champion Serena
Williams suffered her first loss in nearly three months on
Friday as she was knocked out of the Cincinnati Open
quarter-finals, falling 6-4 6-4 to Germany's Angelique Kerber.
While older sister Venus Williams continued her progress and
moved to the semi-finals with a 6-2 6-7 6-4 win over U.S. Open
champion Samantha Stosur, Serena struggled against an impressive
Kerber en route to just her fourth defeat of the year.
Serena, who had not lost since her opening round defeat at
the French Open, complained of fatigue after her last 16 match
on Thursday but she fell on Friday to an opponent who used a mix
of intelligence and technique to make her life difficult.
"It was probably for the best that I didn't win today, even
though I wanted to win. But maybe my body was like telling me
not to. I don't know," said Williams, whose loss came in her
31st match, including singles and doubles action, since the
start of Wimbledon.
"I felt really good going out there today, much better than
my other two matches but it was a false alarm.
"She didn't do too much that threw me off. Her game is
pretty straightforward and you know what to expect. She's
getting a lot of balls back. She played really well today and I
think she served more up the T than I expected."
Kerber, who has reached at least the quarter-finals in 12 of
17 events played this year, double-faulted on match point but on
her third chance used a blistering ace to win the match.
"I had nothing to lose today, I tried to play my best and
take it point by point because she has been playing so well
recently," said world number seven Kerber.
The German's opponent in Saturday's semi-final will be the
winner of the match between Russian Anastasia Pavlyuchenkova and
Czech Petra Kvitova later on Friday.
Venus Williams's recovery from health problems is finally
delivering some results, she reached her first semi-final since
pulling out of last year's U.S. Open with an auto-immune disease
that causes fatigue and joint soreness.
"I'd like to think that this is only the beginning for me of
more semi-finals. Of course I'm going to stay focused and try to
make it to the final as well," said Williams, who will face
either China's Li Na or top seed Agnieszka Radwanska of Poland
in the semi-finals.
"I'd like to take it a lot further. I haven't played a lot
since 2010, so this is awesome for me already."
(Editing by Frank Pingue)