A quartet of unexpected semifinalists are still alive at the MLS is Back tournament.
Philadelphia advanced to the semifinals thanks to a strong defensive performance throughout the competition and its largest offensive output in a single game in the quarterfinals.
The Union face the Portland Timbers, who are the most established of the four franchises left, in the first semifinal.
Portland won the 2015 MLS Cup and it was the runner-up in 2018. To get to the semifinal, the Timbers had to top a group with pre-tournament favorite Los Angeles FC and fend off a quarterfinal challenge from 2019 Eastern Conference regular-season champion New York City FC.