The Storm turned the ball over five times Friday night in a 60-41 loss to the Sharks at Jacksonville Veterans Memorial Arena.
Tampa Bay is 0-6 all time on Jacksonville's home field.
The Storm overcame two early giveaways and a 13-0 deficit to lead 21-20. But after that the Storm offense sputtered, with Randy Hippeard throwing three interceptions and losing two more fumbles.
Jean Fanor's interception return for a score pulled Tampa Bay within 39-35 in the third quarter, but Jacksonville scored the next two touchdowns to put the game away.
Tampa Bay had a chance to take sole possession of first place in the South Division but instead is tied with Orlando (3-2). The Storm travels to Orlando next Saturday.
Jacksonville's win put the Sharks back in the South race at 2-2.
The biggest turnover was the one to start the second half. Tampa Bay was trying to take a lead but instead Hippeard had the ball knocked loose and Sharks linebacker Aaron Robbins took it into the end zone for a 33-21 lead.