A Good Samaritan rescued an elderly man from a car that drove through a backyard fence and plunged into a swimming pool in Long Island, cops said.

Joseph DiDonato,79, was in the parking lot of a foot care doctor in Commack on Jericho Turnpike and Siracusa Boulevard Monday, when he accidentally stepped on the gas of his 2010 Acura SUV, police said.

The homeowner, John Bacchi, was with his wife in the yard, which faces the Mayfair Foot Care center, when DiDonato’s car went flying into the deep end of the family’s pool.

Bacchi immediately jumped into the water, broke the driver’s side window and pulled the man to safety, cops said.

DiDonato was rushed to Huntington Hospital for evaluation, authorities said.