CHESTER, Pa. - A sellout crowd showed up for John Hackworth's debut as the Philadelphia Union's interim manager on Saturday night at PPL Park.

Unfortunately for Hack-worth, a red-hot D.C. United club also showed up.

Chris Pontius scored in the 78th minute to lift D.C. United to their fourth straight victory, 1-0 over the Union.

D.C. United improved to 9-4-3 and moved four points ahead of the New York Red Bulls for first place in the Eastern Conference. It's their first four-game winning streak since the 2008 season.

The struggling Union (2-8-2) saw their winless skid reach six. They haven't won since a 1-0 victory over Chivas USA on April 21.

A crowd of 18,876 showed up to see the Union's first game under Hackworth, who was elevated when Peter Nowak stepped down Wednesday after two-plus seasons.

Hackworth had been an assistant coach under Nowak since the Union's inception in 2010.

But the Union sputtered again offensively and couldn't add to their season total of eight goals. That production is tied with Toronto FC for last in the 19-team league.

D.C. United leads the league with 29 goals.