By Larry Fine
NEW YORK (Reuters) - Three-time champion Serena Williams said Thursday she would turn her concern over sister Venus's illness into motivation at the U.S. Open after pounding her way into the third round of the year's last grand slam.
Williams crushed Michaella Krajicek of the Netherlands 6-0 6-1, losing just three games total at Flushing Meadows so far, the day after twice champion Venus withdrew because of symptoms from the autoimmune disease she suffers from.
"She wants me to do the best. She wouldn't want me to suffer," 13-time grand slam winner Serena said.
"So now, if anything, it should motivate me more."
The five-time Wimbledon champion told ABC's "Good Morning America" television program Thursday that she had trouble with stamina, had swelling, numbness and fatigue, but was confident she could get back on the court.
Serena, 29, said "all I can do is just pray," before adding that just knowing what was sapping her energy was a key step forward for her sister.
"I know she's a fighter and she's really strong. She's great. I think she's really happy now that she knows what it is after all this time."
Serena has had to cope with serious health worries herself.
Last year after winning her fourth Wimbledon singles crown, she cut her foot after stepping on glass at a restaurant in Germany. The injury led to health complications, surgery and a potentially fatal blood clot on her lung.
"I visit kids in hospitals that have cancer, and I just am so amazed at how the families are there and how blessed I am," she said.
"Okay, I had a blood clot or had surgery. Thank God I don't have this other disease. Things can always be so much worse."
Williams is playing the Open for the first time in two years, missing last year's event because of her foot injury.
Her last appearance in singles ended in controversy when she unleashed a foul-mouthed tirade at a line judge and was docked a point that ended her semi-final match against eventual champion Kim Clijsters.
She bristled when asked again about what she learned from the 2009 tantrum that also brought her a hefty fine.
"You just really focus on life and how precious that is. I feel really honored to be out here every match."
Serena said health issues put it all in perspective.
"You know, a bad call here or there really is not the end of the world. It just makes you realize how important life is and how precious life is and how it's really a gift that we should cherish."
(Editing by Julian Linden)