Power tried overtaking the ex-F1 driver in Wisconsin  on Saturday night, and was left irate by Grosjean’s defending.

First the Frenchman seemed to cover to his right, then he swerved forcing Power to harshly brake. 

“Frustrating. I felt like we were really quick. Surprised. Disappointed,” Power fumed.

“And, Grosjean is a piece of crap, if you saw what he did in practice!

“He needs a punch in the face!”

Incredibly Power did get involved in fisticuffs with another driver in the same session.

An incident with Scott Dixon concluded with both drivers putting hands on each other after an angry exchange of views.

“I’m just pissed, what Dixon did this morning just ruined our whole weekend and just a terrible move all up,” Power said.