About 5:28 p.m., James Dobbins, 54, Apollo Beach, was riding a 2009 Kawasaki motorcycle northbound on U.S. 301 in the outside lane approaching Elm Fair Boulevard, an FHP report said.
Damien Jones, 29, was driving a 2003 Monte Carlo southbound and started to make a left turn when he drove into the path of the Dobbins, who struck the passenger side of the car.
Dobbins and his passenger, Amanda Brungard, 28, Apollo Beach, were thrown from the motorcycle and sustained serious injuries, FHP said. Both were taken to Tampa General Hospital where Dobbins is in stable condition and Brungard is listed in serious condition on Thursday.
Charges are pending, according to FHP.