Serena Williams has promised to donate $100 for every ace she serves for the rest of the year to help the relief effort in New Orleans following the devastation wreaked by Hurricane Katrina.
The 23-year-old former world number one made the announcement after beating Catalina Castano of Colombia 6-2, 6-2 on Wednesday to reach the third round of the U.S. Open.
"I would like to thank everyone for coming out," she told the crowd.
"I was just thinking about the hurricane. It's been such a tragedy down there.
"I decided for every ace I hit I am going to donate 100 dollars for the rest of the year, every tournament I play."
Katrina has claimed more than 200 lives, left tens of thousands of people homeless and caused billions of dollars in damage since slamming into the U.S. Gulf Coast on Monday.