Johnson took second from Ty Dillon and closed to 0.310 of a second with 32 laps to go, but his loose condition worsened and he began falling farther back.
Larson was in distance of the checkered flag, but a caution with two laps to go set up an overtime restart with Johnson starting alongside.
When the green flag dropped, Johnson rocketed ahead of Larson, beating the Target driver through turn one to take the lead.
“Obviously I didn’t need that last caution,” Larson said. “Jimmie is the best of our time, probably best of all time. He just has obviously a lot more experience than I do out on the front row late in races, and executed a lot better than I did.”
Coming to the white flag, a nine-car wreck occurred behind Johnson, Larson and Truex to bring out the caution. Johnson had reached the overtime line before the caution flew, so he was shown the checkered flag his next time around the track to claim his 11th victory at the Monster Mile.
Truex rallied from 15th in the final 50 laps for third. He continues to lead the points over Larson by nine.
“Well, for us the ending of the race was really all about trying to pass cars and get back to the front where we’d been all day long,” he said. “We got caught on that caution there with, I don’t know 60 or so laps to go and we pitted. Caution came out, got trapped a lap down, had to do the wave-around and then drive up through the field from the back.
“Definitely proud of our finish today,” he added. “I thought we definitely had a shot at the win until that happened, and after that is was just — we were kind of playing catch-up. At a place that’s really difficult to pass, we had to come from about 15th to get get third. Definitely proud of the run, proud of the effort and the car the guys brought here today.” Follow Caroline/ Dorchester Editor Dustin Holt on Twitter @Dustin_StarDem.