NEWTON, Iowa — It took rookie William Byron just a week to get over one of the most brutal losses of his young career.

The 19-year-old Byron grabbed the lead with just over 20 laps left and won the NASCAR Xfinity race at Iowa Speedway on Saturday night for his first series victory.

A seven-time winner last year in the Truck Series, Byron broke through just a week after an agonizingly close loss to Monster Energy Cup star Denny Hamlin at Michigan.

"Last week was just exciting to be that close to a win," said Byron, who won the Truck race at Iowa in 2016. "It gave us a lot of momentum going into this week."

Ryan Sieg was second in the stand-alone race with the Cup regulars in Sonoma for Sunday's race. Tyler Reddick was third, followed by Ross Chastain and Dakoda Armstrong.

Christopher Bell led 152 laps in just his second career start in the series before a late wreck cost relegated him to 16th. He led a race-high 99 laps in the Truck race Friday night.

Sieg, also in search of his first win, was on Byron's tail on the final restart and nearly overtook him.

But this time Byron, who led 78 laps in JR Motorsports' No. 9 Chevrolet, was the driver with just enough to hang on.

"I gave him all I could give," Sieg said. "He was just a little stronger, a little faster. I did all I could do."

For Byron, the victory was quick redemption after Hamlin beat him by 0.012 seconds.,

"To get second last week kind of hurt because we were that close. But I feel like it gave us extra motivation," Byron said.

As for Bell, he suffered bad fortune for the second night in a row.

Bell, who finished fourth in his debut at Charlotte, won the pole and the first stage. But early in the second stage, Sam Hornish Jr. — who was hoping to win at Iowa in his season debut like he did in 2016 — rubbed fenders with Bell.

Hornish popped a tire and slammed backward into the wall, ending his night.

"I felt like we were heading in the direction we needed," said Hornish, who'll return to Iowa Speedway with Team Penske next month. "This is not how we wanted it to go at all."

Brendan Gaughan took advantage of a late restart to win the second stage and pick up his first playoff points of the season. Bell soon regained control, but he was clipped by Brennan Poole and sustained heavy damage.

Series leader Elliott Sadler, making his 800th career start, qualified fourth but was sent to the back of the field for an unapproved adjustment. Sadler finished eighth after an up and down night.

Matt Tifft was 22nd in his return to Iowa, the first race he missed in 2016 after being diagnosed with a brain tumour.

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