The warm-hearted actor spotted the homeless musician's tatty old acoustic guitar as he stopped to give him a donation.
Just a few minutes later, Robert emerged from a nearby music shop, bearing two guitars —the first for himself and the other for the busker.
Excuse us while we compose ourselves.
Onlookers reported that the busker was "totally shell-shocked" after Rob presented him with his new guitar, but couldn't play it because "he couldn't get his thoughts together."
"We were gob smacked when he handed the acoustic guitar to the [man]," the onlookers told The Sun. "Robert quickly went back to his car and drove off."
Just being face to face with R-Pattz would leave us squealing, let alone an R-Pattz bearing gifts!