It happened just after 4:30 a.m. at 1412 E 21st Ave., said Tampa Fire spokesman Capt. Bill Wade.
Firefighter Eric Stokes was injured putting out the fire and taken to a local hospital, but Wade said the injuries were not serious.
The arson string led Tampa Fire and Tampa police officials to create a task force to investigate and seek neighborhood tips. So far, no arrests have been made.
In Friday morning's fire, however, a witness saw someone sitting on the home's porch before the fire, Wade said. Investigators now have a good description, but they would not release it.
Wade said investigators have identified the man and would speak to him.
"He may have seen something that might lead us somewhere else," Wade said.
Before Friday, the last suspected arson reported in the neighborhood was Dec. 15. That one is still under investigation.
All but four fires involved vacant homes. Some happened in the middle of the day, some overnight. Some were started outside the homes and some inside.
Many burned multiple times. At least four were in foreclosure.
They may have all been set by the same person, or some may be the work of copycats, investigators said.
Most were frame homes close to neighboring houses, which would make it easy for a fire to spread.
Wade urged V.M. Ybor residents to keep the outside of their homes lit, preferably with motion-detector lights. He also suggested communicating with neighbors about suspicious activity, watching out for each other and keeping an eye on vacant homes.
Wade asked anyone with information about any of the fires to call the arson tip line at (813) 274-7133 or communicate online at www.tampagov.net/fire. Call 911 if you see suspicious activity in progress.
"You never know when that one call or one tip is going to lead to a conclusion of this case," Wade said.