Both weekly episodes rank in prime time’s Top 10. “Dancing” draws about 20 million viewers on Mondays and almost 16 million on Tuesdays. The last two seasons have been won by teams including sports celebrities: NFL great Emmitt Smith and Olympic speed skater Apolo Anton Ono. The latter was coupled with Julianne Hough, Castroneves’ partner this season.

A native of Brazil, Castroneves is nicknamed “Spider-Man”; he’s the first driver to scale the track-side fence to celebrate a victory, which he did after his back-to-back wins in the 2001 and 2002 Indy 500. Now 32, he set an IndyCar record this year by winning seven poles out of 16 races. Engaged to Cuban fashion designer Aliette V zquez, he lives in Coral Gables, Fla., but is staying in Los Angeles with the rest of the “Dancing” cast.

To stay in shape outside the race car, the 5-foot-8 driver runs, swims, lifts weights and boxes. He’s also an avid tennis player. He credits his fitness for helping him to bounce back quickly after tweaking his knee and foot during Week 4’s Jive routine. Shifting gears for a moment, Castroneves slowed down enough to chat before tonight’s show: Q: What’s this experience been like? A: I’m having so much fun. I’m so happy; our waltz (last week) went really well.

Julianne told me to dance like I was in the clouds. I think I like ballroom (dancing) more than Latin I know that’s ironic because I am Latin. I guess opposites attract. Q: Are there any similarities between racing and dancing? A: I always tell people, “You’ve got to be smooth smooth on the dance floor, smooth on the racetrack.” If you dance too aggressively, you get in trouble. You’ve got to slow down. Same with driving; you get too aggressive, you crash. You try to stay smoooooth.