Martin Truex Jr., the defending Monster Energy NASCAR Cup champion who dominated the 2017 season, earned his first victory of 2018 Sunday at Auto Club Speedway in Fontana, Calif.

Truex, who started on the pole, ran up front throughout the afternoon, winning the first two stages before scoring the race win, his 16th career victory.

The deciding moment in the face came with 37 laps remaining, when the leaders all pitted. Kyle Busch won the sprint off pit road ahead of Truex, but a problem immediately surfaced. Busch's crew radioed to say they had adjusted the wedge the wrong way on the stop. Five laps later, Busch's loose car bobbled and Truex sped into the lead for good.

"We never gave up on it," Truex told Fox Sports. "I knew we had a really good race car. … Once we got in clean air this thing was unbelievable."

"It's just unbelievable to be able to do this for a living."

Kevin Harvick, who won the previous three races and was favored to win a fourth straight in the Auto Club 400, crashed early in the first stage after running into Kyle Larson's car. Although Harvick's crew made repairs, he returned several laps down and finished 35th.

"I went down to side draft, he was coming up and we touched," Harvick said. "I think that's my fault for coming down the race track … I was trying to get a little too much right there."

Larson overcame that early incident with Harvick to finish second. Kyle Busch crossed the line third, followed by Brad Keselowski and Joey Logano.

NASCAR results from Auto Club 400 at Fontana

1. Martin Truex Jr.
2. Kyle Larson
3. Kyle Busch
4. Brad Keselowski
5. Joey Logano
6. Denny Hamlin
7. Erik Jones
8. Ryan Blaney
9. Jimmie Johnson
10. Austin Dillon
11. Clint Bowyer
12. Aric Almirola
13. Alex Bowman
14. Kurt Busch
15. William Byron
16. Chase Elliott
17. Jamie McMurray
18. Ricky Stenhouse Jr.
19. Paul Menard
20. Darrell Wallace
21. Ryan Newman
22. AJ Allmendinger
23. Daniel Suarez
24. Kasey Kahne
25. David Ragan
26. Michael McDowell
27. Ty Dillon
28. Cole Whitt
29. Ross Chastain
30. Chris Buescher
31. Matt DiBenedetto
32. Gray Gaulding
33. Timmy Hill
34. Reed Sorenson
35. Kevin Harvick
36. Jeffrey Earnhardt
37. Trevor Bayne