Castroneves knew he wasn't going to remain on the front row for long.
Castroneves claimed the pole for Sunday's race at Iowa Speedway, but he will start 11th after an unapproved engine change.
Still, it wasn't all bad news for Castroneves or Penske — which claimed its third pole in seven Iowa races.
Penske teammate Will Power will start first, and Castroneves still earned nine championship points by winning the top heat. Castroneves also extended his lead over defending champion Ryan Hunter-Reay to 25 points in the process.
James Hinchcliffe of Oakville, Ont., will start second, followed by Marco Andretti, Scott Dixon and Ed Carpenter.
"These points, it's always good. It's always crucial when you are fighting for the championship, and every point counts," Castroneves said.
This was the second straight year that the IndyCar series seeded the Iowa field with heat races.
After receiving mixed feedback from drivers and fans, officials tweaked the formula this year.
The runs were extended from 30 to 50 laps, and the heats were set by a single-lap qualifying run rather than practice times.
The first race didn't produce a ton of excitement as Dixon and Takuma Sato advanced with relative ease. Castroneves cruised, as well, leading all 50 laps of his heat before being forced to go to a new engine.
"The good news is my car, as you could see, is really fast. Anything could happen," Castroneves said.
The second heat provided some much-needed drama. Graham Rahal and Simon Pagenaud battled furiously for second and final berth in the last heat, and Rahal passed Pagenaud and then Ed Carpenter to take first.
The strong qualifying run was crucial for Power, who remains in 11th place after finishing second each of the past three seasons.
"I really need to gain some points on those guys, Helio, Hunter Reay, everyone in front of me," Power said. "There's a lot of people in front. But at some point the championship is going to become out of reach."
The biggest concern about heat races was potential wrecks. Those fears were realized when James Jakes lost control and hit the wall two laps from the end of the second heat.
Jakes was checked in the medical centre, released and cleared to drive Sunday, though he will start near the back.
Hunter-Reay, who won last week at Milwaukee and last year at Iowa, was just 14th after qualifying.
"You know, it was way off the mark. We've been sitting on our own thumbs all day. We just missed it," Hunter-Reay said. "We're starting buried in the pack. We gave up points."
Alex Tagliani of Lachenaie, Que., will start 12th.