Rooney, who tied the match 1-1 late in the first half, followed the go-ahead goal by Fisher in the 47th minute with a free kick over the wall in the 68th minute for a two-goal advantage
Wayne Rooney scored twice to lead D.C. United to 4-1 victory over the visiting Portland Timbers at Audi Field on Wednesday to extend their unbeaten streak to four matches.
Oniel Fisher and former Timbers forward Darren Mattocks also scored for D.C., which has three wins and a tie in its past four games.
Rooney, who tied the match 1-1 late in the first half, followed the go-ahead goal by Fisher in the 47th minute with a free kick over the wall in the 68th minute for a two-goal advantage.
Rooney has three goals in seven games for United after scoring 208 goals in the English Premier League for Manchester United and Everton.
Mattocks got his ninth goal in the first minute of stoppage time for the final score.
Samuel Armenteros gave Portland the lead in the 35th minute. The Timbers have lost two straight after a 10-0-5 streak.
Armenteros scored his eighth goal after a cutback pass to him in the middle of the box by Andy Polo, who was the recipient of a pass down the left flank by Sebastian Blanco.
Rooney made it 1-1 in the 43rd minute. He ran into open space for the through ball by Yamil Asad and put a left-footed shot past Jeff Attinella.
Fisher broke a 1-1 tie in the 47th minute as the Jamaican defender scored his first goal in 45 career games with D.C.
A midfield lay off by Rooney put Luciano Acosta free for a run to the box where he fed Fisher on the right channel. Fisher's shot hit the far post before bounding across the line.
Portland stays on the road with a match Saturday vs. Sporting Kansas City. D.C. United is home Sunday against the New England Revolution.