After the resumption from yellow Dixon dived by rookie Robert Wickens to grab second place. He put some pressure on Power but all cars were hard in fuel-saving mode to make it to the flag and he had to settle for second.
"Definitely credit to the team – everybody on the PNC Bank car has been working extremely hard," Dixon said. "We have definitely had a rough start to the season and a rough weekend here.
"We had a good strategy day – there was a period there on one stint where we were almost two seconds a lap quicker than everyone else just pounding around on new tyres and we must have made up about 20 seconds on that stint.
"It is great to finally be on the podium this year.
"Hopefully we can start to set sail and make some championship points up here."
Power was delighted with the race win. He has started in the top four in each of the first four rounds of the season but has run into problems in three of those races.
"It was an amazing race," Power said. "We had to save a lot of fuel at the end and go fast because I know how good Dixon is at saving fuel and going fast but the Chevy had good fuel mileage."
Wickens held on for third while defending series champ Josef Newgarden made a costly error in the latter part of the race to lose some points to his rivals.
The Indianapolis 500 is the next race in the championship in a fortnight.