"The guy said, `Hit the net like any Negro would.' I was shocked," Williams said. "I couldn't believe it. I had to do a double take. I think I hit a double fault on that point."

Williams won the third-round match against Lucie Safarova, 6-3, 6-4. Williams complained late in the match to the chair umpire about the heckler.

"I shouldn't have let it bother me, because growing up in Compton we had drive-bys," said Williams, who was raised in Los Angeles. "I guess that's what my dad prepared me for, but I'm not going to stand for it."

Fans and security confirmed a man heckled Williams inappropriately, tournament director Adam Barrett said.

"The man was identified and escorted off the site," Barrett said. "As security determines the severity of his actions, he may not be welcome to return. We take these matters very, very seriously."

Williams, an eight-time Grand Slam champion, is among the event's most popular players. She lives in South Florida, considers Key Biscayne her home tournament and has won the title three times.

With a small crowd in the stadium for her late-afternoon match, she said she could hear the heckler between points and during them.

"Every time I missed a shot or a serve, he would say, `That's the way to do it,"' she said. "He was calling, `Foot fault.' He was saying, `Hit in the net.' ... I mean, who does this? That's so elementary. You don't do this on a professional level."

Williams and her sister Venus have boycotted the Indian Wells tournament since 2001, when the family was booed after Venus withdrew just before a semifinal match against Serena. Their father, Richard, said those jeers were racially motivated.