Sergio Santos also scored, driving a left-footed shot off D.C. United goalkeeper Chris Seitz's hand and into the net in the 21st minute. Jose Martinez provided a long ball from just behind midfield to an open Santos, who had plenty of space for his shot.
The Union, which ran their undefeated streak to seven matches, were in firm command throughout, and could have gone to halftime with more of a lead. A giveaway deep in the United end almost produced a fourth goal for Philadelphia, but Alejandro Bedoya just missed the target in the 41st minute.
Santos hit the post with a shot in the 53rd minute. Erik Sorga had a good chance for D.C. United that just missed wide right.
United is winless in six straight matches.
The Union completed their near-perfect night, making it 4-0 when Przybylko crossed to Brenden Aaronson for a 61st-minute goal. D.C. United pulled one back on Julian Gressel's first of the season in the 63rd, the shot glancing off Union goalkeeper Andre Blake's hands.
Union defender Kai Wagner left the game in the 27th minute due to injury.
- 7’ — PHI — Kacper Przybylko | WATCH
- 16’ — PHI — Kacper Przybylko | WATCH
- 21’ — PHI — Sergio Santos | WATCH
- 61' — PHI — Brenden Aaronson | WATCH
- 63' — DC — Julian Gressel | WATCH
- THE BIG PICTURE: The Union keep rolling. They took control early and hardly let up, taking advantage of some key names not playing for the visitors. The long passes from Martinez and Olivier Mbaizo that set up goals were pinpoint, showcasing another way Philadelphia can score. For D.C. United, no Bill Hamid, no Paul Arriola, no Frederic Brillant or Steven Birnbaum meant several young players in the lineup. and the group faltered early though it played better after 25 minutes. Coach Ben Olsen said Hamid "needed a few days for some personal stuff," and added that Birnbaum and Brillant had ankle injuries that he didn't feel are significant, with the hope they can return to practice this week.
- MOMENT OF THE MATCH: Przybylko's second goal saw him switch the ball from his left to his right at the top of the box and fire a low shot that got past Seitz for the Union's second goal.
- MAN OF THE MATCH: Przybylko, with a brace and an assist. He was a handful for D.C. United all night.