United shaded the chances but, like its season, fell short in the end. Sporting secured home-field advantage through the playoffs by topping the East.
Sporting fired an early warning when Kei Kamara's spinning cross found Omar Bravo woefully unmarked in the box, but the Mexican somehow managed to flub the shot and send it spiraling harmlessly high.
D.C., already eliminated from playoff contention, had the better of the chances from then out. Captain for the day Dwayne De Rosario in particular looked to add to his league-leading 16 goals, with his best chances - a deft chip from distance and the follow-up to a spilled Santino Quaranta shot - finding the wrong side of the crossbeam.
In the second half, Kamara was involved again. The forward headed a corner off the upright. Matt Besler muscled onto the loose ball, turned around, and shot the eventual winner.
In stoppage time, Josh Wolff powered a header off Jimmy Nielsen's crossbar. Nielsen made three saves in his seventh shutout of the season. D.C. failed to score for the first time in eight matches.