Rahal was denied his first race win in the series since 2017 when Dixon, who suffered an opening-lap spin, pulled off a remarkable comeback drive on an alternate strategy.
It meant Rahal caught him in the closing stages, but Dixon had stored more overtake allocation - due to fuel saving - and so was able to deploy his push-to-pass (which at the Indy road course was 200s in total for the race, in a maximum burst of 20s) to keep Rahal behind.
Dixon won the race by 0.4s for his 54th career victory on his record-setting 319th consecutive start for Chip Ganassi Racing.
“Frankly, I almost had it, meaning like I needed about one more car length to be closer out of [Turn] 13 to be able to get by,” said Rahal. “But I pulled off of [using the] overtake [aid], because I wasn't really gaining. I was kind of just holding steady.
“Because of his race pattern being so much more fuel saving, he had a lot more overtake at one stage. We were catching him at the end. He was starting to use overtake. At one point he had 60 seconds more than me.
“I think at the end we ended up equal. He was using it to stay ahead of me.”
In spite of Dixon using the engine power-boosting system as a defensive weapon, rather than one to create overtaking, Rahal said the situation was a fair fight that he prefers to F1’s solely aerodynamic aid.
“That's what I kind of love about our version of overtake frankly,” he said. “It's a mano-a-mano battle.
“You use it offensively, defensively. None of this DRS crap that makes it easy. For me, I thought Dixon used it right today.
“I tried to do the best I could to challenge him. I just ran out of steam.
“I mean, leading up to the last lap, I went through the snake, turn seven, eight, nine, 10, I had zero grip. I lost about half a second, three-four tenths. That was it.”
Rahal did criticise the length of the full-course caution after the opening lap, which meant the race didn’t restart until lap eight – which was a potential game-changer for Dixon’s fuel strategy.
“I asked the guy, ‘I don't know why we're not going green – this doesn't make any sense’,” he added. “I knew when Dixie pitted, I was like ‘son of a...’
“You give the guy an inch, he's going to get a mile. He's the best at saving fuel, going fast, doing the things he does. I did that exact strategy two years ago, so I knew it worked.”
