NASCAR’s DANICA PATRICK’s red-hot romance with RICKY STENHOUSE, JR. spins out after he made her crash on the race track, say  sources.

Patrick, 31, who began dating the six-years-younger racer on the heels of her split from husband Paul Hospenthal last November, was running strong May 26 at the Coca Cola 600 in Charlotte, N.C.

But Stenhouse clipped the side of her No. 10 Chevrolet, shoving her into NASCAR champ Brad Keselowski and sending both smashing into the wall. Patrick continued racing – as Ricky roared past scot-free – but limped to a 29th place finish.

Later, Patrick said the accident was “unfortunate,” but a source says it may be only the

tip of the iceberg for problems between the newcomer Sprint Cup lovebirds.

“Ricky had hell to pay when they met up after the race. There’s no sport more fiercely competitive or where tempers get raised more than NASCAR – and Danica is famous for having a short fuse,” the source says.

“Ricky and Danica are going to run into each other again and again, and racing veterans are taking bets this relationship doesn’t reach the finish line.”

Even though Keselowski took the blame following the race, saying, “I cut her off,” a source says, “It was clear Ricky caused the crash – Danica said as much on her radio communication with her pit crew during the race. And she was spitting mad he made such a bone-headed mistake!

“She’s trying to keep her professional and personal lives separate, but it gets harder to do when you’re competing against your boyfriend.”

Even before the 2013 Sprint Cup season started, Stenhouse vowed he wasn’t going to go easy on his girlfriend, adding, “I want Rookie of the Year just as bad as she does.”

And since the crash, Danica has serious concerns about the future, insiders say.

“Ricky helped her get over the end of her marriage to Paul and is great to her when they’re not strapped into their race cars,” the friend says.

“But they’re competing against each other in a highly volatile sport, and Danica worries that the dog-eat-dog world of racing will destroy her chance of lasting love with Ricky.”