BIRMINGHAM, Ala. -- NBCSN viewers couldn't tell that Josef Newgarden was nervous with three-time Verizon IndyCar Series champion Scott Dixon, who with 36 wins is fifth on the all-time Indy car list, was within striking distance in the closing laps of the Honda Indy Grand Prix of Alabama.

The steely 24-year-old Tennessee native "drove my race," maintaining his line in the No. 67 Hartman Oil CFH Racing Chevrolet and keeping his foot to the floor on the 2.3-mile, 17-turn Barber Motorsports Park road course to claim his first Verizon IndyCar Series victory in his 55th start.

Only in the post-race interviews was Newgarden unmasked.

“I can’t tell you how nervous I was. In racing I am normally not, but it’s just been such a long time coming in trying to do this," he said. "I can’t believe now is when it happened."

Newgarden is the fourth different winner in as many races this season. He delivered the sixth win for the team he's spent his entire four-year career with after winning the Indy Lights championship, and it was the first victory since the merger of Ed Carpenter Racing and Sarah Fisher Hartman Racing announced last August.

"The car, the team made it easy on me. They deserve the victory. I knew that one of these days it was going to happen with this team because they are so solid," said Newgarden, whose previous best finish was second (2013 Baltimore street circuit, 2014 Iowa oval). "Let's go to the next one and try to do it again."

Rahal overtook Verizon P1 Award winner Helio Castroneves for third on Lap 82 to move into contention.

"I'm really proud of these Steak 'n Shake guys. They've worked extremely hard and today I drove that race 110 percent every single lap," Rahal said. "Honda did a great job for me today. This team has come a long way and I think we have proven that. Eventually, one of these days we'll win one of these things. I hope everybody enjoyed the race because we were pushing there until the last second."

Dixon, who won a week earlier on the streets of Long Beach, Calif., finished third in the No. 9 Target Chip Ganassi Racing Chevrolet. He has podiums in all six races at Barber Motorsports Park (four runners-up, the past two years in third).

Reigning Verizon IndyCar Series champion Will Power, who won at Barber in 2011 and 2012, placed fourth in the No. 1 Verizon Team Penske Chevrolet. Ryan Hunter-Reay, who won the past two races at Barber, finished fifth in the No. 28 DHL Andretti Autosport Honda.

Castroneves had to pit on the white flag lap and placed 15th -- one position behind Team Penske teammate Juan Pablo Montoya, who maintained the series championship lead by three points over Castroneves heading to the Angie's List Grand Prix of Indianapolis on May 9.

"There was just a bit of miscommunication on our fuel number that, unfortunately, caused us to have to pit with one lap left," said Castroneves, driving the No. 3 AAA Insurance Team Penske Chevrolet. "We were on the same strategy with (Josef) Newgarden and (Scott) Dixon, but we were needing to meet a different fuel number than they were and I didn’t understand that. So I was trying to balance making the number we had to meet with not giving up a position to Dixon, who was behind me. Unfortunately, that caused us to come up short.

"I hate it because the AAA guys gave me another car that could’ve easily won the race, but it was a crazy race out there.”

Newgarden, who started a season-high fifth, led a field-high 46 laps -- more than double his previous career total. He placed eighth after starting fourth at Barber Motorsports Park last year.

“I just can’t think everybody enough that gave me an IndyCar job," Newgarden said. "It’s unbelievable what this has turned into. Chevrolet was incredible. I was just getting crazy fuel mileage with fast pace."