The Phillies loaded the bases with one out in the bottom of the inning but could not score after Roger Bernadina struck out and Freddy Galvis grounded out to end it.
The homer was the fourth of the season for Lucas. Miami's Giancarlo Stanton tied the game 3-3 in the sixth inning with a two-run, homer to center field that was measured at 460 feet.
Brad Hand (1-1) was credited with the victory for pitching a scoreless ninth. Steve Cisek was shaky in the 10th but picked up his 31st save overall and 26th in a row, the longest active streak in the major leagues and one shy of the Marlins' franchise record set by Todd Jones in 2005.
Cesar Jimenez (1-1) took the loss as Miami snapped its seven-game losing streak to Philadelphia.