Toyota refers to Hamlin’s action as a “grievous mistake,” and NASCAR penalises him severely.

DAYTONA BEACH, Fla. — NASCAR docked Cup Series driver Denny Hamlin 75 points and 10 playoff points Thursday, eliminating any shot he had at winning the regular-season title and making his path toward a championship more difficult.

The hefty penalty was handed down because Hamlin’s race-winning engine from Bristol Motor Speedway in March was rebuilt by manufacturer Toyota before NASCAR could tear it down and inspect it. The sanctioning body also fined Hamlin’s crew chief, Chris Gabehart, $100,000.

Toyota Racing Development self-reported the “grievous mistake,” as TRD president David Wilson called it, and NASCAR issued the same penalty that would get handed to any team that alters its engine before being inspected.

Hamlin, who was third in the Cup standings and 28 points behind leader Tyler Reddick, drops to sixth and out of contention for the regular-season title with two races remaining. His playoff points fell from 21 to 11, leaving him less room for error in the opening three races of the postseason.

Wilson said the manufacturer takes full responsibility and added that Hamlin’s team, Joe Gibbs Racing, was not involved in the engine disassembly.

“TRD is solely responsible for the handling and disposition of all our engines pre- and post-race,” Wilson said in a statement. “Despite procedures being in place, Denny’s race-winning engine from Bristol was mistakenly returned to our Costa Mesa facility (in California), disassembled and rebuilt instead of being torn down and inspected by NASCAR per the rulebook.

“Although we know with absolute certainty that the engine was legal and would have passed inspection, we left NASCAR in an impossible position because they were not given the opportunity to properly inspect our engine.”

Wilson said Toyota has implemented several additional steps to ensure that “this never happens again.”