Chris Rolfe scored twice as Chicago Fire came from behind to beat Philadelphia Union at PPL Park.
The hosts opened the scoring, courtesy of a Jalil Anibaba own goal, in the 34th minute.
Chicago were level nine minutes later when Rolfe thumped home from eight yards following a clever pass from Sherjill MacDonald.
The turnaround was complete in first-half stoppage time as Arne Friedrich headed in from a Marco Pappa corner kick.
Rolfe struck again 11 minutes after the break with a powerful long-range shot that flew into the top left corner.