The win in the Toyota/Save Mart 350 Monster Energy NASCAR Cup Series race was the Joe Gibbs Racing driver's third at Sonoma and his fourth overall in 2019.
"What a season we've turned this into," said Truex, the 2017 Cup champion.
"This group. They're unbelievable. Hopefully we can keep this going."
He led a race-best 59 of the event's 90 laps.
Finishing second was teammate and fellow 2019 four-race winner, Kyle Busch.
"Sucks finishing second to a teammate but it's good for the company," Busch said. "Martin's really, really good here so I'm just pumped that I actually ran good here."
Truex's margin of victory in 2018 was just over 10 seconds. The margin Sunday was 1.861 seconds, but no other cars were within 20 seconds when the checkers waved.
Ryan Blaney of Team Penske finished third, Matt DiBenedetto of Leavine Family Racing was fourth and JGR's Denny Hamlin was fifth.
The redesign of Sonoma for this year's Cup race transformed last year's 12-turn, 1.99-mile layout into a 15-turn, 2.52-mile course. Added to the reconfiguring was the sweeping down-hill "Carousel" turn.
"I wasn't sure this weekend how it was going to hold up from what we've been doing with the Carousel and the big left-hand corner," Truex said. "It really changed things up. Took a while to figure that out in practice but luckily we were able to make the right tweaks."
Kevin Harvick, an eight-race winner a year ago and the winner at Sonoma two years ago, is still looking for his first victory of 2019. He finished sixth.
Northern California native Kyle Larson started the Sonoma race from the pole for the third time, but his lead lasted for just a couple of turns as he was quickly passed by William Byron. Byron blew out to a five-plus-second lead and easily won the 20-lap first stage.
Byron's Hendrick Motorsports teammate, Chase Elliott, started Stage 2 with the lead but was immediately passed by Truex. As did Byron in Stage 1, Truex used the clean air out front to pull away from the field. He gave up the lead when he pitted just before the end of the stage. Hamlin took the lead and won the stage.
Busch challenged over the final laps but couldn't get into position to make a winning pass.
"He was obviously saving a lot," Busch said. "I knew he was going to be saving a lot. Enough to most likely be able to hold us off and I was right but I still tried everything I could to get there and run real hard."
Source: The Jamestown Sun