You know your song is big when ESPN sportscasters reference it during baseball highlights. And that song has lifted Chamillionaire from Texas mixtape king to chart-topping rapper.

"With 'Ridin,' it's a street concept. We're rapping faster. It's not the average single," Cham said last week from the Bay Area. "For it to go #1, it's pretty amazing. We ain't soaked it all in yet. We're looking at the charts and seeing what songs it's above, and wow. The competition is pretty amazing. We always had faith though."

If you've tuned in to the radio in the past few months, you've probably heard Cham's song about the rapper being racially profiled by police who are trying to catch him with contraband, such as guns or drugs, in his car.

"It's a lot of them that show love," Chamillionaire said about police. "They try to be extra cool, like, 'I'm not one of them bad cops.' "

Recently though, while on a trip to Oklahoma, Cham said the police weren't too cool to his crew. The MC said a squad car pulled over his tour bus on the highway, and officers rifled through everyone's belongings. Cham, who wasn't present for the search, said the police saw that his tour bus was wrapped with his face and logo and began harassing the people on the bus.

"My face is on the side of the bus real big," Cham said. "The cops brought out the dogs and everything. They were asking for me. I guess they was really talking trash. They didn't find nothing. They tore the whole bus apart. They said that normally when they take somebody to jail, they play Afroman's 'Because I Got High.' But they said since it was a special occasion, they were going to play 'Ridin.' It was crazy."

His bus was clean, Chamillionaire said, so no arrests were made. In a separate incident, Cham said he came across an e-mail from an irate police officer who thought "Ridin" was unfair.

"[He said] all cops were not bad and I had to remember that cops put their life on the line for people like us," Chamillionaire said. "He said something along the lines of, 'Next time you make a song like that, think of cops who aren't with their families that protect other people's lives.' "

Cham scoffs at the notion that his hit record is not true to life.

"Man, it ain't about everybody; just the cops who try to catch you ridin' dirty," he said. "Somebody had to speak on it. There are cops who be racially profiling. They're acting like [racial profiling] is new. Once somebody starts exposing it to the mainstream, they start complaining."

No one in the music industry is complaining about Cham. His debut, Sound of Revenge, which was released late last year, has sold almost 1 million copies. He's been getting calls from a slew of artists who want to work or tour with him. So far, he's done verses for Baby and Lil Wayne's upcoming duet LP, Like Father, Like Son (see "Busy Lil Wayne Says 'I Am The Kobe Bryant Of Hip-Hop' "), and he's also worked with Ciara, Joe, Young Buck and newcomer Jibs.

"Everybody started seeing those record sales come up, and then they was like, 'Let's go get on the road with Chamillionaire,' " Cham said.

So how did he graduate from regional street favorite to the top of the charts? He never left the streets. During the past year and a half, Cham and his team have had one of the most successful grass-roots promo runs in hip-hop, taking a city-by-city approach to winning over fans and gaining exposure.

Cham's next single is called "Grown and Sexy" but will have to wait until "Ridin" cools off to be released. There are still several remixes coming.