"We can't stop right now, because the championship is still wide open," said Castroneves, who opened a 22-point lead over Marco Andretti in the standings.
Indeed, there's no security in being the front-runner through eight races – seven which have produced different winners. Eleven races remain on the diverse schedule, including two street circuit doubleheader weekends that carry full points for each race and sets of two short oval and two superspeedway events.
"A win, certainly, is a great feeling," Castroneves added. "A championship, I don't know that yet, and I would love to have that feeling at the end of the season."
The three-time Indianapolis 500 winner has been agonizingly close to the title multiple times in 11 IZOD IndyCar Series seasons, including a runner-up to Sam Hornish Jr. in 2002 and to Scott Dixon in '08.
Consistently running up front when the checkered flag flies is a strategy as old as the Indianapolis Motor Speedway to produce a championship season. Castroneves has four top-five and seven top-10 finishes overall – all by qualifying no higher than fifth in the opener at St. Petersburg.
"We've got to be consistent when you have opportunities. At this point, just got to keep moving," said Castroneves, who broke a tie with Johnny Rutherford for 12th on the all-time Indy car list with his 28th victory and first on an oval since September 2010 at Twin Ring Motegi. "(This week), got to turn the page and focus on the next race."
That's the Milwaukee IndyFest on June 15. In 12 previous races at the one-mile oval, Castroneves has three pole starts and a best finish of second among four top 10s. Current championship rivals Ryan Hunter-Reay, who is 27 points off the pace, won at The Milwaukee Mile last year to jump-start his drive to the championship. Tony Kanaan, who's fourth in the standings, was last June's runner-up and like Hunter-Reay is a two-time Milwaukee winner. Andretti has one pole and two top-10 finishes in six starts.
The stretch of five races on consecutive weekends concludes June 23 at Iowa Speedway, where all of the top five in points have had success. The first Indy car event at the 2.5-mile Pocono Raceway since 1989 follows July 7 before the bulk of the street/road course schedule kicks in.
"Tony and I were on the podium for the next two races last year, and then we have some new challenges," said Hunter-Reay, who claimed his maiden series title in a season-finale shootout with Will Power at Auto Club Speedway. "I like Pocono being on the schedule, it's a new challenge and it will make everybody think, take everybody out of their comfort zone a little bit.
"But we have doubles at Houston and Toronto, and there's a lot of curveballs coming at us, so it should be an interesting championship. I think it will come down to the end, the last race like it always does.