PORTLAND, Ore. — Despite a multicar pileup on the opening lap that sent the pole winner Alex Palou to the back of the pack, Palou managed to cleverly work his way back into the IndyCar championship lead and place first on Sunday at the Grand Prix of Portland.

“I can only believe it that we found our way to victory,” said Palou, a 24-year-old Spaniard fighting to keep a points lead he has held for most of the season. “I don’t care that much we have the championship points lead. I would just be trying to win the race. I did that today!”

Palou finished 1.2895 seconds ahead of Alexander Rossi. Scott Dixon, the six-time IndyCar champion and defending champion, rounded out the podium. All the top finishers, including Jack Harvey in fourth place, drove Honda-powered vehicles, crossing the finish line ahead of the leading Chevrolet-powered competitor Josef Newgarden in fifth.

Palou, despite a crash in a practice warm-up on Saturday, had come back to win the No. 1 starting position. It had been a stunning comeback, but he was sidetracked again when the race’s start caused a chain pileup in the first turn.

“I did not know what had happened behind me at the start, until I felt followers ramming into the back of me,” Palou said afterward, shaking his head. “Until I noticed it was my teammates.”

Dixon, his top teammate, plunked him on one side and Felix Rosenqvist, a former Chip Ganassi Racing teammate, got him on the other. Dixon said after the race that he thought the start would lead to a “terrible” outcome for the team.

“Huge congratulations to Alex for overcoming that, and coming back, and heading for the championship,” Dixon said.

Palou decided after the collision to have his car inspected. No damage was found, he said.

“I thought, ‘Let’s top up the fuel and get the best tires.’”

Though that initial decision pushed Palou to nearly dead last among the 27 scorers, he slowly started to pick his way back to the front. “I knew how my strategy change,” he said, “and how it could work well.”

Palou had to overcome an early lead from Pato O’Ward, who had avoided the congestion. But even O’Ward had been tagged from behind. “I think I am OK,” he radioed to his crew. “But I am not sure until I can be checked in the pits.”

The early leader, at least from a visual standpoint, seemed to be Graham Rahal, whose car had been uninvolved in the start mesh. But Rahal is closing in on a fourth consecutive season without a win. Ultimately, depleted fuel blunted his best efforts.

Meanwhile, Palou kept clawing his way back up front. Halfway through the race, Palou said, he received encouragement from his pit man Dario Franchitti, himself a former IndyCar champ and three-time Indy 500 winner.

“You are doing the right thing,” Palou said Franchitti told him. “You are in the right place. Keep doing the same thing.”

Despite retaking the lead, Palou became worried when an unexpected yellow-flagged caution bunched the field again — thanks to a collision between a couple of back-markers.

“No, you are still in the catbird seat,” Dixon was heard radioing Palou’s crew.

Yet even with a plan in place, another back-marker yellow flag came out with just a few laps to go. When the green flag waved to restart the remaining competitors, Palou found the power needed to keep Rossi from overtaking him, even though Rossi was reported to have greater passing power.

The victory was Palou’s third best scored by the IndyCar series this season so far, and gave him a 25-point lead that will be tough to beat, even though two races in California, at Laguna Seca and Long Beach, have been added to the schedule.

“Winner, winner, chicken dinner,” Palou cheered in a victory circle, saying that Franchitti, who runs a popular fried chicken restaurant in the Portland area, had already invited him for a victory feast. “I’m ready for chicken dinner!”