Rowe opened the scoring in the 26th minute with a long strike and the lead held up through the first half.
The Union got a tally from Danny Cruz early in the second half to forge a 1-1 tie.
The Revs went ahead for good in the 58th an own-goal by Philadelphia's Amobi Okugo, and Rowe made it 3-1 with his second goal of the game 7 minutes later.
Diego Fagundez and Juan Agudelo added late scores for the Revs (10-9-6), who moved into fifth place in the Eastern Conference with 36 points.
The Union (10-8-8) retained fourth place in the East.