ESPN IndyCar

DETROIT -- The IndyCar Series championship battle was pushed to the back burner Sunday by a popular victory for Justin Wilson and Newman/Haas/Lanigan Racing in the Detroit Indy Grand Prix presented by Firestone.

Wilson's first IndyCar Series win came at the expense of Team Penske's Helio Castroneves, who incurred a controversial penalty for blocking on the 72nd of 87 laps.

Meanwhile, pit strategy again doomed championship leader Scott Dixon's race, as the Target/Ganassi driver finished only fifth. Dixon's IndyCar Series points lead was trimmed to 30 heading to next weekend's season finale at Chicagoland Speedway, where an eighth-place finish will secure the crown for the New Zealander no matter what Castroneves does.

Sunday at Detroit, most of the talk was about how Wilson drove a stealthy race and finally forced Castroneves into a mistake that might have a critical impact on Helio's championship aspirations.

Two laps after a restart, Wilson got a superb run on the No. 3 Penske entry, prompting Castroneves to weave from one side of the track to the other. His actions were caught by ABC's cameras, and Indy Racing League chief steward Brian Barnhart almost immediately ordered Castroneves to let his rival by.

The blatant block was obvious to everyone but Castroneves and anyone else wearing a red-and-white Team Penske uniform.

"Obviously there are two sides to every story," chuckled Wilson, who won four Champ Car World Series races prior to joining the IndyCar Series this year. "From my position, Helio slid a little bit through Turns 10-11-12. We went into 12 on the brakes and he overshot and I cut back to the inside and got some great traction. Before we had even got to full power I was inching along side him and I thought, 'This is pretty straightforward. By the time we hit the brakes we'll be axle to axle and I'm on the inside.'

"But to my surprise he came over, then he came over more until the point where I had to just back out. I even braked. It was pretty severe, and I guess they figured it deserved a penalty."

Castroneves didn't agree, and said the move he pulled was no worse than anything else he has done during the course of his seven-year IndyCar Series career.

"That was a very difficult situation and in my opinion, this is a situation that is unusual," Castroneves said. "Since I've been here in 2002 I always did that and at least you got a warning. But all of a sudden I had to give the position to him.

"That was an unusual call and I don't know why [Barnhart] did that. I don't know if other teams or people were putting pressure [on him], but Brian is not typically a guy to receive that. If you want to be consistent with rules, you have to start from the beginning, especially if you are battling for a championship."

Barnhart defended his judgment call, which was supported by several replays.

"We talk about blocking every week in the drivers' meeting and tell them what they can and can't do and what the code of conduct is on the racetrack," Barnhart said. "[Castroneves] clearly moved his car to impede the progress of a following car and moved his car in response to the actions and the line taken by a following car.

"We made the same decision early in the race with the [Darren] Manning and [Bruno] Junqueira cars and unfortunately you have to call it like you see it. You can't officiate based on points or who's involved or what position they hold. You have to do it out of fairness and competition."

Castroneves led every tour of the Belle Isle Park street circuit but one from Lap 19 until he was asked to let Wilson past. He and his team were still quietly seething after the race.

"I'd rather for us to have gotten a run on [Wilson] with Helio not blocking so he could pass him cleanly," observed Penske Performance president Tim Cindric. "Then the fans would have understood and maybe there wouldn't be this discussion. But hey, they're the officials and it is what it is."

Maybe the most frustrated driver was Dixon, whose team called him in for his first pit stop on Lap 18 during a full-course caution. Most of the leaders stayed on track and pitted about 15 laps later, leaving Dixon stuck in the fifth position he would occupy for the rest of the race.

"It was not much of a race, and in fact it was pretty pitiful for us," Dixon said. "But we win as a team and we lose as a team. I think my anger or whatever is caused by frustration. I think we clearly had the quickest car today and nobody was going to touch us. That's disappointing. That's what makes it tough to deal with. At Sonoma we didn't have the greatest race car and were maybe hoping for a top-5 at best. But here we had a car to win."

Instead, the win went to Wilson, who was regarded as the heavy favorite in the Champ Car World Series this year until that series was folded into the IndyCar Series in the spring.

Graham Rahal scored a tactical victory for Newman/Haas/Lanigan Racing at St. Petersburg, but Wilson and the celebrated team have generally struggled in their first season in Indy cars. Wilson finally broke through for a podium finish last month at Edmonton.

"This is the highlight of my racing career, winning a race for great owners like Carl Haas, Paul Newman and Mike Lanigan," Wilson said. "I'm very privileged to be driving for them and to get our first victory in our first season in Indy cars when times have been so difficult … we've had so much happen this year and we've had so many occasions when I thought we were in contention for a podium if not a win, and things just haven't gone our way.

"It's tough to keep going away and saying, 'That's racing.' You have to keep picking yourself up and moving on and I'm very happy to have finally got a win this year and keep my streak going of winning a race every season [since 2005]."

Wilson's only downer was that he didn't get the opportunity to make a clean pass on Castroneves for the lead. Not that he is complaining.

"[The penalty] definitely was a little bit surprising, but to my mind, it was so clear and obvious that I think something had to be done," Wilson said. "In my eyes, I knew I had to make a very decisive move. I didn't want to get tangled up with Helio and in the middle of the championship battle.

"You just have to do what feels right in that split second. I'm not trying to get in the way of the championship, but I'm trying to win out there. People came out here to see a race and they don't want to see guys just driving around. That was my opportunity to race and I was pretty frustrated it didn't get to a proper overtaking maneuver."

John Oreovicz covers open-wheel racing for National Speed Sport News and ESPN.com.