NEWTON, Iowa (AP) High school diploma in hand, William Byron seems to have already found his calling.
Byron held off the field on a late restart to win the NASCAR Truck Series race at Iowa Speedway on Saturday night for his second straight victory.
The 18-year-old Byron held off a hard-charging Cole Custer by less than a half-second for his third victory in just nine career starts.
Byron also is 2-0 in trucks since graduating from Charlotte Country Day school in North Carolina - and he's just 11 points behind Matt Crafton in the season standings.
''We've kind of hit our stride in May and now June, and we've been able to focus on what we need to do better,'' said Byron, who will attend Liberty University, the sponsor of his No. 9 truck, in the fall. ''I wouldn't say it's related to graduating high school, although it's definitely a relief.''
Custer was second, followed by ThorSport Racing teammates Cameron Hayley and Ben Rhodes.
Tyler Reddick, who led 37 laps, was fifth.
The first 150 laps or so didn't provide much action, with only a mandatory caution clock keeping things interesting.
The finish showed why drivers often rave about Iowa's 0.875-mile oval.
Reddick had clean air and the lead with 22 laps to go. But Tommy Joe Martins and Derek Scott Jr. got collected in the backstretch, drawing a red flag to clean up fluid on the track.
The restart saw multiple drivers jump out in front, and at times the battle for first went three-wide.
But another accident drew the final caution flag of the race. Once the green flag was raised, no one had enough to overtake Byron.
''After that red flag, things definitely multiplied by about a thousand,'' Hayley said. ''(Byron) made the best moves at the right time.''
John Hunter Nemecheck earned his first career pole earlier Saturday, and he led the first 53 laps before Byron surged ahead after a caution.
Byron seized control from there, leading by as much as five seconds over Ben Kennedy. That big lead was largely wiped out by the caution clock halfway through the race, but Byron was still able to set a personal best with 107 laps led.
Kaz Grala went sideways with just over 50 laps left. Byron's truck stalled as he left his stall, pushing him down to 11th and Reddick into the lead ahead of a wild finish.
''When it came down to those last couple of restarts, I just knew that we could try the outside. I just kept moving up and up and up. I kept getting blocked, and finally I made it three-wide. It just worked out,'' Byron said.
Despite failing to catch Byron, Hayley and Rhodes put forth strong showings for ThorSport, which saw its headquarters rendered unusable after a fire tore through the building on Monday.
''We only had two trucks for this race. We only have two trucks for the next race. So it's really hard to try to race for a win and have that in your mind,'' Rhodes said.