Chris Hemsworth celebrates his 40th birthday by'sweating off the birthday cake'.

Chris Hemsworth knows how to throw a knockout punch.

The Thor actor celebrated his 40th birthday with a flurry of events, including a boxing practice session the day after.

In an Instagram video, a shirtless Hemsworth is seen sparring with a training partner in an indoor and outdoor gym.

As the two men fought, Hemsworth immediately fired a few jabs to his partner's gloves.

The August 15 video was captioned, "Sweating off the birthday cake with @Centr."

Hemsworth did consume a lot of birthday cake on August 11, when he took an Instagram photo with two chocolate confections topped with Happy Birthday candles.

"Thank you so much for all of the birthday wishes!" he added. "Yet another lap around the sun and I'm still going strong!"

 "I can safely say that not a single piece of cake survived the night."

Blac Chyna is dedicated to her exercise program and wellness journey.