Larson's pit crew catapulted him into contention during the final stop of the race, leaving pitroad just ahead of his title rivals.
On the ensuing restart, he went three-wide for the lead with Denny Hamlin and Ross Chastain. He managed to clear Hamlin, who had only taken two tires, but not Chastain.
As the Trackhouse Racing driver pulled away, Larson was left to fight a charging Blaney in the closing laps.
"I needed to come out the leader on that restart," lamented Larson to NBC. "Ross [Chastain] got a really good start from the second row. I was hoping I could get clear of Denny [Hamlin] and get the lead and then have Ross protect for me, behind me. I'm not sure if it would have made a difference. I was just not as good as a few other guys, especially Blaney and Ross probably. It would have been difficult."
Larson got sideways through the dogleg with Blaney right behind him. The two drivers went side-by-side into Turns 1/2 and down the backstretch, making slight contact. Blaney then managed to cleared Larson from the outside lane and with 20 laps still go.
Larson was never able to mount a counter-attack, saying: "I'm at peace knowing that that was all I had today. I know it didn't look maybe like it that last run. That was all I had. Our team did a really good job of putting us in that spot.
"I am still obviously extremely bummed, as I'm sure Denny [Hamlin] was last week. Even though I didn't feel like I had the fast car, I had an opportunity. It's a bummer when you don't win.
"At the same point, I'm probably coming up this close, probably more eager for the following season already. I know where I need to improve and I'm just ready to get back on the track and work on all that."
"Yeah, bummed but also eager to get into the off-season, get working and ready for next year."
Looking back on the battle with Blaney, Larson knew he was going to be "trouble" as the Team Penske Ford quickly closed in.
Yeah, I mean, when I saw him get to third as quickly as he did, I knew I was going to be in trouble.
"He could just move around a lot better than me, kind of be more comfortable on the edge," said Larson. "He definitely looked loose, but he could still push the car. I couldn't push the car really further than what I was.
"I felt really committed to the bottom. Even when I would move around and make my car feel better, it was slower on lap time. I knew I was in a little bit of trouble and was going to try to put up a fight. Yeah, I felt like I wasn't going to be able to hold him off.
"He did a really good job. His team continued to improve on the race car throughout the last few months. Yeah, they deserved to win."
Larson ends the 2023 season with four wins, 15 top-fives and 18 top-tens through 36 races.
