Zac Efron surprises fans in Melbourne as he joins star-studded crowd at the F1 Australian Grand Prix

Hollywood star Zac Efron surprised fans in Melbourne on Sunday at the Australian F1 Grand Prix.

Efron, 36, was joined by a star-studded crowd on the pre-race grid at Albert Park.

At one point, the High School Musical star was seen chatting with Australian actor Sam Worthington, 47.

Efron kept it casual in a black long-sleeved T-shirt and opted for a pair of stylish sunglasses as he looked around the Oracle Red Bull Racing garage.

Award-winning actors Eric Bana and Rachel Griffiths also got in on the trackside action, along with Dylan Alcott, Andy Lee and Rebecca Harding, Samantha Jade, Bailey Smith and Chris and Bec Judd.

Among those in attendance were Channel Ten stars Melissa Leong, The Inspired Unceived, Jonathan LaPaglia, Grant Denyer and new MasterChef judge Jean-Christophe Novell.

American actor and comedian Jeremy Piven also appeared at the Grand Prix. The 58-year-old was a guest in the Paramount Suite.

Piven is in Australia for his new live comedy show, which will take to the stage in Melbourne on April 2 and Sydney on April 4.

Efron’s surprise visit to Australia comes after he previously spent a full year in Australia in 2020 to escape the Covid-ravaged United States.

Zac primarily resided in Byron Bay, where Thor actor Chris Hemsworth owns a $30 million mansion.

He also filmed Stan’s Original film Gold in South Australia and filmed scenes for his Netflix documentary series Down to Earth.

He found love in Australia with Byron Bay waitress Vanessa Valladares, but they split in April 2021 before he left for North America.

They are believed to have met for the first time in June 2020, when Vanessa was waiting tables at the Byron Bay General Store cafe.