A man who lent a stranger his cell phone had his generosity poorly repaid Saturday, when the borrower responded with a beating when the phone owner tried to get his device back.

Police say that the gesture of kindness turned sour at 1:50 Saturday morning, when a man in his 20s asked a 22-year-old man if he could borrow the latter's cell phone as the two walked down the 600 block of Mission Street, which is between Second and Third Streets.

However, when the phone owner lent the borrower his phone, the borrower "did not use the phone and began to slowly walk away," according to the San Francisco Police Department.

The phone owner then "attempted to get his phone back," but the borrower-turned-thief instead punched him, pushed him, and fled.

The victim suffered non-life-threatening injuries as a result of the attack. The suspect remains at large, police say, and no arrests have been made in the case.

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