Two U.S. Open Cup heavyweights will do battle tonight with a spot in the final on the line.
The Philadelphia Union and Chicago Fire have been constants in the latter stages of this competition over the past several years. The Fire have made 13 Open Cup semifinal appearances in their 20-year history, more than any other team, while the Union are already making their fourth appearance in the penultimate round of the tournament.
The two teams have met in the Open Cup once before, when the Union triumphed in the 2015 semifinal.