Both players were reinstated from the 10-day injured list, the team announced before the game.
Harper and Schwarber were injured in the same game against the Miami Marlins in late June. Harper suffered a left hamstring strain, while Schwarber suffered a left groin strain.
After a modest 5-4 mark with Harper and Schwarber sidelined - that included dropping two of three over the weekend in Atlanta - the Phillies flexed their muscle early against the Dodgers in a matchup of NL division leaders.
The Fightins', with help from a Trea Turner grand slam, defeated the Dodgers 10-1 in the first of the three-game series.
The Phillies lost ace Zack Wheeler on a steamy night with left lower back tightness after five innings.
Wheeler won his 10th game of the season. He joined Aaron Nola and Ranger Suárez as a trio of Phillies pitchers with 10 wins before the All-Star break.