Dominant in defense of last year's victory in the Toyota/Save Mart 350, Martin Truex Jr. held off Kyle Busch, his Joe Gibbs Racing teammate, to win Sunday's Monster Energy NASCAR Cup Series event at Sonoma Raceway.

With three-lap fresher tires after the final set of green-flag pit stops at the 2.52-mile road course — which for the first time since 1997 featured use of the carousel connecting Turns 4 and 7 — Busch closed an 8.269-second gap to slightly more than a second over the last 24 laps.

But the driver of the No. 18 Toyota could get no closer, given that Truex's No. 19 Camry had better drive off the corners at the 12-turn course and was able to keep Busch at bay. Truex led three times for 59 of the 90 laps, including the final 24.

"I just dug down deep and tried to be smooth and hit my marks," said Truex, who won for the fourth time this season — all in the last eight races — the third time at Sonoma (including two straight, and with three different car owners) and the 23rd time in his career. "Luckily I began with a big enough gap where I could get away and not feel too much pressure.

"It was definitely a battle going on, as far as the race there at the end for us on tires. It felt terrible the last 20 laps. The last 10 it just felt like it was on ice — just no grip anywhere. I'm really proud of all these guys and everyone on this team and everyone back at JGR.

"What a season we've turned this into. This is great, man, unbelievable. Hopefully, we can keep it going."

Joe Gibbs Racing has won 10 of the first 16 races this season. Truex, who moved from now-defunct Furniture Row Racing to JGR this year, has now posted at least four victories in four straight seasons, including the current one.

And with Matt DiBenedetto running a career-best fourth and Stage 2 winner Denny Hamlin driving from 26th to fifth in the final stage of the race after pitting during the second break, Toyota placed four drivers in the top five. The only interloper was third-place Ryan Blaney in a Team Penske Ford.

With four laps left, Busch had trimmed Truex's advantage to 1.542 seconds, but Truex ultimately expanded the edge to 1.861 seconds at the finish.

"Yeah, any time I had to lean on the left rear, I just didn't have the drive that I needed," Busch said. "Actually tried to hold on to it, trying to save it. I knew that was going to be our problem — that had been our problem all day long. You get closer, you're like, 'OK, I can get him, I better go, pounce on him fast, so then he doesn't have the time to pick up the pace.'

"But it didn't work. He was obviously saving a lot. I knew he was going to be saving a lot, have enough to be able to most likely hold us off. I was right. I still tried everything I could to get there and ran real hard. … Sucks to finish second to a teammate, but it's good for the company. Overall Martin is really, really good here. I'm just pumped that I actually ran good here."

Kevin Harvick and Ryan Newman claimed the sixth and seventh spots. Erik Jones, who started from the rear of the field after his team made repairs to the left rear quarter of his car post-qualifying, was eighth in the fourth JGR Toyota.

Aric Almirola and polesitter Kyle Larson completed the top 10. The winner of three straight poles at Sonoma, Larson posted his best finish at the road course.

The race ran caution-free, except for the two stage breaks. Front-row starter William Byron grabbed the lead from Larson on the first lap and won the stage wire-to-wire, but he lost track position while pitting under caution during the stage break and finished 19th.