Castroneves, desperate to steal a win and any kind of gain on the Target Ganassi Racing points leader, tried a fuel-conservation plan at the Meijer Indy 300. On Turn 3 of Lap 200, he felt golden.
Coming out of Turn 4, he was toast.
Dixon, in a season in which everything is going right, reeled in the sputtering, fuel-starved Team Penske No. 3 in the final laps, blowing by in the frontstretch to win his sixth race and add another 13 points to what appears to be an insurmountable 78-point lead.
Castroneves was left with an agonizing seventh runner-up in 14 starts, wondering what else he can possibly do just to get the top spot on the podium.
"We need to take chances to win a race," Castroneves said. "This was a solid chance, not a ridiculous, crazy chance."
His Dallara-Honda wasn't going to finish in the top five -- much less win -- by conventional methods. For a second consecutive year, the Penske contingent wasn't good at Kentucky from the minute it unloaded, with Ryan Briscoe and Castroneves qualifying only on the third row in fifth and sixth overall.
Castroneves ran just inside the top 10 through the meat of the 200-lap affair, and with 57 laps to go came in for fuel and the team decided he wouldn't see pit lane again the rest of the night.
"We had a ninth- or 10th-place car, the only chance we had to improve on that was to give it a shot," said Tim Cindric, Penske Performance president and Castroneves' race strategist. "We were just a little bit short, but Helio did a great job trying to get what we could out of it. I guess today we're happy to be second."
They haven't had a choice this season. Saturday was the third consecutive runner-up day and second straight bridesmaid finish to Dixon. Two weeks ago at Edmonton, Castroneves led 35 laps and was hot on Dixon's trail late after the 2003 champion got a boost from his Target crew on pit lane and took the lead. But Castroneves missed his mark heading into Turn 1 at City Centre Airport and Dixon was able to pull away over the final five laps to a five-second victory.
Castroneves also finished second to Dixon in June at Texas Motor Speedway. In five other races where the Brazilian has finished third, fourth or fifth, Dixon has finished ahead of him every time, including a spotlight win in May at Indianapolis.
"Any other circumstances, I would probably be leading the championship," said Castroneves, who also ended up on the wrong end of a fuel strategy race to Danica Patrick at Twin Ring Motegi. "Scott is just having a fantastic year."
Thanks in large part to Dixon, Castroneves' winless streak is now at 29 races, the longest of his IndyCar career. He last won at St. Petersburg early last season, and since then Dixon has bagged 10 wins. The New Zealander also will stand in the way of a first series title for the No. 3 barring a collapse over the last three races.
"It's funny, Scott Dixon says to me, 'Man, every time I win, you finish second,'" Castroneves said. "I say, 'Well, every time I finish second, you finish first. We've got to change that. You've got to finish behind a little bit and let me win.'"
Doesn't look like that's going to happen anytime soon.
John Schwarb is a motorsports contributor to ESPN.com. He can be reached at email@example.com.