BRISTOL, Tenn. -- Sleet fell during the Food City 500 at Bristol Motor Speedway.
And that might not have been the most unusual thing that happened in a race that took about 26 hours to complete.
A Keselowski spin with 30 laps remaining allowed Busch -- who at the time was doing everything he could do to keep his car stable with the worn tires -- to pit for tires, setting up his late charge for the victory Monday afternoon.
Busch, who restarted second with 22 laps remaining, put the bump-and-run to Kyle Larson with six laps left for the win, his seventh in a Cup car and 21st at Bristol across all three national series.
When asked after the race if the fact that Keselowski's spin was a benefit meant he went up a notch in Busch's book, Busch laughed.
"That's pushing it too far. ... I kind of felt bad for him maybe just that much," Busch said holding his index finger and thumb together with very little distance between. "But it certainly helped our cause, so that was much appreciated. Let's just go with that."
After two days of poor weather, most drivers were just appreciative to get out of Bristol, a track on which the upper groove never really was the place to go and the pit gun problems of past weeks once again doomed at least one potential winner.
Busch teammate Denny Hamlin had to pit while leading because of a loose wheel, finishing a lap down in 14th. He was one of two JGR drivers to have loose wheels on the day. JGR had developed its pit guns last year to the point where they had an advantage, and they feel the NASCAR-issued pit guns are breaking or malfunctioning too often -- a common complaint throughout many top teams.
"For our sponsors and everybody, I'm calling, trying to explain it, and it's hard to explain," team owner Joe Gibbs said.
Busch didn't have a wheel problem, just a tire-rubber problem on a long green-flag run in the cold temperatures. Keselowski's tire issue, one in which the tire was coming apart, forced him to nurse his car around the track prior to the spin.
At that time, Larson had the lead on Ricky Stenhouse Jr., and Busch, in third, was wondering if he would have to pit under green.
Busch crew chief Adam Stevens didn't even realize the irony of Busch's rival helping him out. The Busch and Keselowski teams were pitted next to each other all day.
"It's just another competitor, another team to me," Stevens said. "But it's a good group of guys. We were pitted beside them and worked well together, even when we were behind them.
"It seemed like Kyle gave their guys room, and Brad and [crew chief] Paul [Wolfe] gave us room. I think there's probably more in the media or maybe in those two drivers' minds than there is between the teams for sure."
In addition to Busch and Keselowski often being in each other's heads, Busch is in Larson's head a little bit when it comes to Bristol.
Larson, who led a total of 272 laps in the Cup races last year at Bristol that were won by Jimmie Johnson and Busch, led a race-high 200 laps in this race but once again was foiled and once again saw Busch as the victor.
"We've been beat by Kyle about every time I race here, too," Larson said. "That gets frustrating after a while."
Johnson finished third, followed by Stenhouse and Alex Bowman in a race that started Sunday and included three red flags for rain, with one lasting overnight. By the time the race resumed Monday -- after a series of brief sleet storms -- the temperatures had dropped more than 20 degrees, hovering around 40.
NASCAR had applied traction compound to the lower groove before the race resumed (but before another quick, freezing rain forced NASCAR to dry the track) and a top groove -- one that potentially could have helped Larson -- never truly came in.
"I just think on the short run and as cold as it is, there's just enough grip to use the shortest way around to create lap time," Johnson said.
"Once the tires wore enough, then you'd move up. But if you put us in yesterday's temperatures, I think we would have been up higher a lot sooner."
That wasn't much solace for Larson, who was too loose on the last run to make the bottom work. Busch made his move a little earlier than would be traditional -- he gave Larson six laps to get back to his bumper, and Larson never could. Larson barely held off Stenhouse before being outdueled by Busch.
"I just didn't have any grip," he said. "I thought it would tighten up for me."
It didn't. And Busch won with more than a half-second to spare.
"You tend to try to want to think about saving that bump and run deal for the last lap, but I just took my chance with it, and if he got back to my rear bumper, then so be it," Busch said.
"I think that's fair game and being able to race that way. Fortunately, I was able to run away from him and he couldn't get back to me."
Busch maybe got a little fortunate in that sense. Or maybe he's just that good.
"I was not planning on it being 39 degrees when we were picking shocks and springs for this thing, so there was a fair amount of adjustment that we had to do," Stevens said.
"And Kyle had to do the rest behind the wheel."