MLS Eastern Conference leaders the Philadelphia Union suffered a setback as they slipped to a 2-1 home defeat against the Colorado Rapids on Friday.

The Rapids went ahead after 35 minutes through Pablo Mastroeni and extended their lead on the stroke of half-time courtesy of Sanna Nyassi's effort.

Any hopes of a Union comeback were extinguished in the 64th minute when Sheanon Williams was sent off, though they did pull one back in the dying seconds when substitute Roger Torres struck.