Helio Castroneves thrust himself into the IndyCar Series championship race today by winning at Edmonton, his second victory of the season.

The Brazilian relied on pit strategy from his Penske Racing crew to take the lead, then held off hard-charging Takuma Sato over the final 15 laps to pick up the win. It moved him one spot in the standings to second - he jumped over teammate Will Power - and he’s trailing leader Ryan Hunter-Reay by 23 points with four races remaining.

The win, in the first caution-free race of the season, snapped Hunter-Reay’s three-race win streak.

Castroneves said when his engineer called him into the pits for an early stop, he wasn’t sure the strategy was correct.

‘‘I was a little concerned to be honest,’’ he said. ‘‘In the end, what a great strategy. I did it, if you believe it, it was so awesome.’’

Kiwi Scott Dixon, who started 18th, moved up eight spots to finish 10th, leaving him fourth in the championship - behind Hunter-Reay, Castroneves and Power.

Leader Alex Tagliani pitted after Castroneves, who had to push to maintain track position after his stop. He slid by the exit to pit lane seconds before Tagliani made it back onto the track, with Sato right behind Tagliani.

Power had been the leader, gave it up to make his late pit stop, and Castronves moved to the lead. Sato got by Tagliani and worked the final 15 laps, to no avail, to catch Castroneves.

He instead settled for a career-best second-place finish, which team owner Bob Rahal jokingly predicted as he watched Sato try to chase down Castroneves.

‘‘Helio is tough,’’ Rahal said. ‘‘He starts blocking when he picks up his rental car at the airport.’’

Power wound up third - his best finish since his win at Brazil in April - and said he was happy with the result. An engine change after qualifying cost Power 10 spots on the starting grid, so he came from 17th to finish third - his fourth podium finish at Edmonton in four years.

Although he dropped a spot in the standings, his deficit was cut from 35 points to 26.

‘‘Awesome day, very good day,’’ he said.

But there was some drama at play as Hunter-Reay believed Power should have been penalized by IndyCar for cutting him off as Power exited pit lane earlier in the race. Power said he believed he had executed the move exactly how race director Beaux Barfield explained it Sunday morning.

‘‘Well, I thought in the driver meeting if you are not cutting someone off, you can take the apex, and I thought I was in front of him because I didn’t see him,’’ Power said. ‘‘But if I was in his position, I guess I would scream for a penalty, too, because that’s more points.

‘‘If that was the case, my mistake.’’

Hunter-Reay, who won the pole but started 11th because of an engine change, was adamant on his radio that Power had broken the rule. And he was furious when no penalty was called after a review by race control.

‘‘You’ve got to be kidding me. That is absolutely... ridiculous,’’ he yelled.

He finished seventh, and still didn’t agree with the ruling after the race.

‘‘I expected it to be called, I expected him to be thrown off, but it didn’t happen,’’ he said.

Although he managed a top-10 finish, he wasn’t pleased because Castroneves and Power gained ground.

‘‘We didn’t lose too much, I guess, but when two guys who are fighting for the championship finish on the podium, it is not very satisfying,’’ Hunter-Reay said. ‘‘We have a lot of racing to go, we need to be strong across the board. This was definitely a bruise today, but it didn’t knock us down, by any means.’’

Graham Rahal finished fourth and was followed by crowd favorite Tagliani, who took the lead on the first lap by passing Dario Franchitti and led 49 laps en route to his best finish of the season and best of his career at Edmonton.

‘‘I thought it was our chance to get in the lead and try to see if we could control the race, and our car was very strong on saving fuel early,’’ Tagliani said. ‘‘We just missed it at the end. We didn’t have the pace that the guys were running at the front. Nevertheless, fantastic result.’’

- AP