Apparently pulling off the signature "Baywatch" beach run is harder than it looks -- at least for Zac Efron.

The "High School Musical" star is currently filming a big-screen adaptation of the long-running lifeguard series opposite Dwayne Johnson, and it looks like the shoot is not without its hazards.

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Efron made the best of a nasty -- or at least embarrassing -- on-set stumble that took place during one of the series' signature runs along the beach with his co-stars, during which Efron found himself literally head over heals.