For the 2004 season, Hornish joined Castroneves at Penske after De Ferran retired from IndyCar; at first, the two did not speak to each other often because of their differing personalities. He led most of the season-opening Toyota Indy 300 before Hornish passed him on the final lap to win. Castroneves qualified eighth for his fourth Indianapolis 500. A lack of horsepower against the Honda-powered cars caused him to finish the rain-shortened race ninth. Two races later, Castroneves' first pole position of the season came in the SunTrust Indy Challenge at Richmond, where he finished third. He took eight more top tens, four pole positions, and overtook Andretti Green Racing's Dan Wheldon to lead the final 21 laps of the season-ending race at Texas for his only win of 2004. Castroneves' finished fourth in the drivers' championship with 440 points.