NASCAR: Youth has his day at Indianapolis

William Byron’s first trip to Indianapolis Motor Speedway ended with an unforgettable finish.

After taking the lead with 15 laps left, the teenage rookie used some savvy moves and a little luck Saturday to hold off the hard-charging Paul Menard for his third NASCAR Xfinity Series win in less than a month. The margin of 0.108 of a second was the narrowest in race history, and he did it by successfully blocking the 2011 Brickyard 400 winner for the final two laps while dealing with a troublesome tire for the final 20.

At 19 years, 7 months, 23 days, Byron became the youngest winner of a major race on Indy’s historic 2.5-mile oval. Brazil’s Matheus Leist set the previous mark in May when he won the Indy Lights race at 19 years, 8 months, 19 days.

And in three weeks, Byron has visited victory lane at two tracks — Daytona and Indy — that often torment more experienced drivers.

Eight drivers traded the lead 16 times, both race records. And before Menard pressed the issue, Byron had to hold off Joey Logano, who finished third more than three seconds back.

Less than an hour after watching one winning streak at Indianapolis end Saturday, Kyle Busch started working on another. Now the two-time defending Brickyard 400 champion is in the best possible position for an unprecedented three-peat at the track.

Busch became the first Cup driver in nearly two decades to win back-to-back Indy poles by saving his fastest lap for the final one of the day. His speed of 187.301 mph was almost a mph faster than second-place Kevin Harvick and was the second-fastest pole-winning speed in the race’s 24-year history.

Harvick’s No. 4 Ford was second at 186.332 and Jamie McMurray, in the No. 1 Chevrolet, wound up third at 186.274.

Busch drove in both of the morning’s Cup practices, qualified for the NASCAR Xfinity Series race in the early afternoon and watched his four-race Indy winning streak ended after a late pit stop dropped him from first to 21st. Busch finished 12th.

He had better success qualifying for the Cup race, to be run on Saturday.

sports@latimes.com