"This is huge for us. This means more to me probably than any race I've ever won or anything," said Mayfield outside the court house after the ruling was announced by U.S. District Court Judge Graham Mullen.

Mayfield tested positive for methamphetamines during a random drug test in May, but Mullen noted the likelihood of a false positive in issuing the temporary injunction.

"The truth came out and now I can go back and say now we're cleared of all this," said Mayfield. "I cleared my name and now we can go back racing again. It feels good to get this off our back and now we can move forward."

It's not known if NASCAR will appeal the ruling.

Mayfield has claimed his positive test resulted from taking the prescription drug Adderall XR, used to treat attention deficit hyperactivity disorder, and a double dosage of the allergy medication Claritin-D.

The 40-year-old Mayfield became the first driver to be suspended indefinitely since NASCAR's revised drug policy went into effect earlier this year.