preparation for the Cup Series race on the same track, new to the schedule, that weekend. It was his first Truck start since 2006, coincidentally also in the No. 51, but he ran for Billy Ballew Motorsports in 2006. He won the race for his first truck series win, becoming the 36th driver to win in all three top NASCAR Series. Despite leading the most laps (122) at the Cup event, Truex would finish 19th after a cut tire with 2 laps to go while running in third. Two weeks later, Truex won at Martinsville for the third time in his career, his sixth win on a short track, and became the 1st driver to win multiple races in 2021. On May 9, Truex dominated and won the Goodyear 400 at Darlington, earning his 30th career victory, and second at the famed track. At New Hampshire Motor Speedway, Truex was running second when the rain hit the track causing Truex, Kyle Busch and Denny Hamlin to crash. He soon rebounded to finish 12th in the same race, which was shortened due to darkness. During the rest of the season, he would continue to perform to the best of his ability for the next 3 races after that, earning a 3rd place finish at Watkins Glen International. Truex was involved in a wreck at the Indianapolis Motor Speedway road course late in the race, but managed to finish 15th. He also scored a top 10 at Michigan International Speedway. Truex was involved in the big one at the Coke Zero Sugar 400 at Daytona International Speedway, resulting in a 29th-place finish. When the Playoffs started, he scored 1 win at Richmond Raceway, a top 5 at Darlington Raceway, and a top 10 at Bristol Motor Speedway. In the second round of the playoffs, he would finish 4th at Las Vegas Motor Speedway, 12th at Talladega Superspeedway, and 29th at the Charlotte Motor Speedway Roval. In the final round of the playoffs at Texas Motor Speedway, Truex got loose in turns 3 and 4, snapping the car around and causing him to slam into the outside wall. He would be scored 25th as a result of said crash. However, he would gather enough points and positions in the next two races at Kansas Speedway and Martinsville Speedway, finishing 7th and 4th respectively, giving him just enough points to advance into the Championship