Mike Quinn, competing for the third-string quarterback job, moved Miami 44 yards in the final 1:03 to set up Mare's game-winning kick, a 42-yarder. The Pro Bowl kicker finished 5-for-5, also scoring from 26, 21, 54 and 25 yards.
Tampa Bay's reserves, helped by two long kickoff returns, rallied with two fourth-quarter touchdowns to take the lead.
The Dolphins' first team played the opening half, rushing for 76 yards, converting six third downs and controlling the ball for more than 18 minutes. But they led 6-0 at halftime because of two turnovers by Damon Huard.
Steelers 13, Panthers 0: The Pittsburgh Steelers turned one of injury-depleted Carolina's three turnovers into Kordell Stewart's 4-yard scoring run and their third consecutive preseason victory.
Kris Brown kicked field goals of 53 and 33 yards, one just before halftime.
Panthers receiver Patrick Jeffers, who ended last season with five consecutive 100-yard games, tore a knee ligament and was lost for the season.
Jeffers, a former Cowboy, was injured in the first quarter when a Steelers player â€“ possibly, cornerback Chad Scott â€“ rolled up on his knee as he was being tackled on a 3-yard completion.