Zac Efron has won a year's worth of Thai massages after beating Dwayne Johnson in a bet.

The Hollywood stars have formed a close bond thanks to their new movie Baywatch, the big screen version of the cult ‘90s lifeguard show.

During Sunday night’s (05Feb17) Super Bowl the film dropped a hilarious new trailer, which showed buff actor Zac stripping down to pair of tiny Speedos decorated with the American flag.

Sharing the clip on his Instagram page, Dwayne admitted he didn’t think Zac would go through with the embarrassing wardrobe choice so he lost their bet.

"You don't get to say that, you're just tan" ~ Mitch Our new #SuperBowl spot. Enjoy! #Baywatch MAY 26th... * I bet my dude @zacefron a years worth of Thai massages (not from me) he wouldn't wear these Snuffaluffagus (sic) huggers in the spot. He did. I lost. Freedom wins.”

Dwayne was referring to Sesame Street's Snuffleupagus, a woolly mammoth-type character with a long nose that nearly reaches the floor.

Dwayne plays Mitch Buchannon in the movie, a role made famous by David Hasselhoff in the TV series. He and Zac are joined by Priyanka Chopra, Kelly Rohrbach and Alexandra Daddario, who Dwayne previously starred alongside in disaster film San Andreas.

Baywatch originals David and Pamela Anderson are set for cameos in the summer movie, which begins hitting cinemas from 10 May (17).