But Rosenfels' pass intended for running back Charlie Rogers was tipped away by Bucs linebacker Jack Golden, securing the Bucs' victory.
Rosenfels, who took over for Brian Griese late in the second quarter, earlier had hit wide receiver Ronald Bellamy with a 2-yard touchdown pass earlier in the fourth quarter as the Dolphins began their comeback from a 20-6 deficit.
Kicker Olindo Mare had provided the Dolphins' scoring in the first half, hitting field goals from 27 and 38 yards out.
But for most of the first three quarters, it was tough sledding for the Dolphins, beginning with a Randy McMichael fumble on a reception on their second drive of the game.
The first-team defense also had a tough time, allowing 126 total yards in the first quarter.
Tampa Bay converted the McMichael fumble with a 6-yard touchdown by Michael Pittman, who raced untouched through the middle of the Dolphins defense.
The Bucs made it 13-0 when they capped a 74-yard drive with a 5-yard pass from Shaun King to Joe Jurevicius. A missed extra point kept the lead at 13.
Tampa Bay made the score 20-6 when Thomas Jones scored on a 1-yard run late in the third quarter.
Griese completed 6 of 8 passes as the starter. Jay Fiedler sat out the game because of the back problem that sidelined him from practice this week.
Injuries were a problem early in the game, with fullback Rob Konrad (finger), rookie linebacker Eddie Moore (foot), long-snapper Ed Perry (knee) and wide receiver Sam Simmons (neck) all being forced from the game.