The score had been tied at 1-1 since the fifth inning when the Marlins finally broke through against Collin Balester (1-4).
John Buck singled to open the 13th and gave way to pinch-runner Brett Hayes. After Greg Dobbs struck out, Murphy drove a 1-1 pitch over the wall in left-center. It was the first home run of the season for Murphy, who has only 14 of them during seven seasons of limited action.
Clay Hensley (5-6) struck out the side in the 12th to get the win and Leo Nunez worked a perfect 13th for his 36th save.