A Best Buy deliveryman allegedly doused a woman with a liquid chemical and beat her to death after installing her washer and dryer in Florida, cops said.

Jorge Luis Depre Lachazo, 21, arrived at the Boca Raton home with his co-worker to install the appliances on Monday and was eventually left alone with Evelyn Udell to explain how to use the devices, according to the Boca Raton Police Department.

The co-worker suddenly heard screams and ran inside to discover the 75-year-old Udell lying on the floor covered in blood.

Lachazo then hopped into the delivery van and fled, cops said.

Udell was rushed to Delray Medical Center, where she died Tuesday.

When he was apprehended, Lachazo admitted that he struck the woman and set her on fire.

The man also told police he had used cocaine and marijuana earlier in the day.

The suspect was charged with murder, arson and armed burglary.