ALERT: Big-time "Grey's Anatomy" spoiler ahead, proceed with caution...

For fans of the long-running TV series "Grey's Anatomy," the death of Dr. Derek Shepherd marked a shocking plot twist, as well as the end of an era for actor/racer Patrick Dempsey, who bids farewell to a 11-year run with the world-renowned medical drama.

Dempsey's character was killed off in Thursday's episode, ironically in a car accident. His final scenes were filmed earlier this month in Seattle, just hours before he flew to Silverstone for the season-opening round of the FIA World Endurance Championship.

With his filming commitments complete for the year, Dempsey's now able to shift his entire focus to racing, as he takes on his first full season of the globe-trotting sports car championship at the wheel of a Porsche 911 RSR.

"In the past I've had too many things go on," Dempsey told FOXSports.com at Silverstone. "You end up making sacrifices. At this level, you have to be in the car, you have to train properly, you have to eat properly.

"It's takes complete commitment. I want to do well and be competitive. It takes a lot more work to do that. We have the team and the resources to have the results."

He's already putting his extra time to good use, with Dempsey and co-drivers Patrick Long and Marco Seefried testing in Bahrain this week, in preparation for the season finale in November. A trip to Dubai for a Porsche event is also planned.

Next weekend, Dempsey will take part in the second round of the FIA WEC at Spa-Francorchamps, the final race prior the double points-paying 24 Hours of Le Mans, where he'll be making his fourth appearance in the French endurance classic.

In many ways, 2015 has marked a fresh start for Dempsey, both professionally and personally.

Not only has Dempsey and longtime racing partner Joe Foster ceased operations of Dempsey Racing in the U.S., he and his wife, Jillian Fink, filed for divorce in January, less than three months prior to his final "Grey's" episode.