US gymnast Simone Biles had an adorable fangirl freak out when Zac Efron surprised her in Rio

For most of us, it doesn't get much better than winning a gold medal. But by the look on the face of Simone Biles in these photos, it was a surprise visit from Zac Efron that really made her day.

The American gymnast – a four-time gold medallist at Rio – has made no secret of her adoration of the High School Musical star. She even has a cardboard cutout of him in her bedroom...

Zac has also publicly declared his support for America's 'Final Five' gymnasts in posts that Biles has been merrily retweeting throughout the Olympics

But we bet nothing prepared her for the moment Efron showed his face in Rio.

The actor surprised the 19-year-old and her teammates Laurie Hernandez, Madison Kocian and Gabby Douglas last night after Biles had captured her fourth gold on the floor.

And of course, she took to social media to chronicle the entire thing...

?? just call me mrs.efron already @ZacEfron pic.twitter.com/FF4NTgj4MP

— Simone Biles (@Simone_Biles) August 16, 2016

We reckon this could be the Start of Something New...