Manchester United's Juan Mata, right, celebrates scoring their third goal of the game with teammates Ashley Young and Wayne Rooney, left, during the FA Premier League match at Old Trafford in Manchester, April 12, 2015. [Photo/SIPA]

MANCHESTER, England - Manchester United ended two years of hurt on derby day by dismantling Manchester City in a 4-2 win in the Premier League on Sunday, underlining the reversal in fortunes of the local rivals this season.

City had won four straight Manchester derbies since April 2013 but the "noisy neighbors" - as former United manager Alex Ferguson once called them - were silenced in another sign of United's resurgence under Louis van Gaal.

United's sixth straight league win came despite City, the soon-to-be-deposed champions, going ahead through Sergio Aguero's eighth-minute opener.

Ashley Young and Marouane Fellaini scored to put United ahead at halftime, before more poor defending by City was punished by goals from Juan Mata and Chris Smalling in a seven-minute span midway through the second half.

Aguero grabbed a late consolation for City but it couldn't stop a sixth defeat in eight matches, a staggering decline that has left City manager Manuel Pellegrini fighting for his job.

City has slumped to fourth place, four points behind United and 12 adrift of leader Chelsea in a brittle title defense. The champions were tied on points with Chelsea on Jan. 1.

"We are not in a good moment," said Pellegrini, who rebuffed questions about his future. "We have a bad 2015 and a very bad week."

City has inflicted some painful defeats on United since its rise as a force in the English game over the last few years, notably last season when it won 4-1 at home and 3-0 away on the way to a second title in three years.

The hurt will have subsided with this win, and the swagger is back at Old Trafford under Van Gaal.

"(The fans) can go on the streets with their hats up and say, 'This year, we are the better team,"' said the Dutch coach, who was careful to play down talk of a permanent power shift in the city.

For the moment, though, the teams are heading in opposite directions.