It was after 1 a.m. Sunday, and Tony Stewart still was making the rounds at Lowe’s Motor Speedway, talking with the media and stopping for a champagne toast to celebrate his victory in the UAW-GM Quality 500.

Eighteen hours earlier, at 7 a.m. Saturday, gates opened to the Grand National series garage to begin a very full day at the Charlotte track. Rain Friday night had set up the unique day-night doubleheader that should have been enough racing to satisfy anyone.

Stewart isn’t just anyone. After collecting his 17th career Cup victory by running down Ryan Newman in the main event, Stewart was looking ahead to his plans for Sunday.

U.S. Auto Club sprint cars were part of the Charlotte race week schedule, and Stewart owns two teams that compete in the series in which the Indiana native cut his racing teeth and where his true racing passions still lie.

Since those teams’ cars were here anyway, Stewart decided to follow his “have to” racing on Saturday with a little “want to” racing for him and some of his buddies Sunday. So Stewart rented out a local dirt track and rolled out his sprint cars for the guys — some of whom were also racing Saturday at Lowe’s Motor Speedway — to enjoy.

“We’re just going to go have fun,” Stewart said after his second Cup victory of the season Saturday night.

Stewart had fun in the UAW-GM Quality 500, too, of course, because he had a good enough car to keep Ryan Newman and his team from parlaying a necessity-born strategy of short-pitting with 67 laps left into their ninth win of the season.

Newman, fearing a vibration on his Dodge was being caused by loose lug nuts, stayed out just long enough to get within his fuel window for completing the race.

Newman had made that kind of strategy pay off in victories several times earlier this year, including a week earlier at Kansas. And when everyone else came in to make their final pit stops, he wound up nearly eight seconds ahead of Stewart with just 36 laps to go.

“I didn’t know he had pitted early until I got out and saw on the board that we were second,” Stewart said. “And then Zippy (crew chief Greg Zipadelli) said the No. 12 car pitted real short and got a big jump with the fresher tires.”

Once Stewart stopped, though, the fresher tires were on his car. He whacked away chunks of Newman’s advantage at first, and soon had the leader in sight. After he had battled by Johnny Benson’s lapped car, Stewart didn’t need anybody to tell him anything. He knew what he had to do from there, and on Lap 327 he finally found his way past Newman.

For Stewart, the victory was a blow for racing purity. He was happy, he said, that the fastest car finally won out over “fuel mileage and strategy” stuff.

Stewart won’t win the title this year. He’s seventh in the standings now, 623 points behind leader Matt Kenseth.

But for Tony Stewart, whether it’s gunning for a first-place check of $312,478 in front of 140,000 fans at Lowe’s Motor Speedway or just goofing off with buddies in a sprint car on a dirt track, just flat racing is what it’s all about.