The Los Angeles Galaxy have hammered the Philadelphia Union 5-1 in their MLS clash at the StubHub Center.

The Union could have taken the lead in the eighth minute when Zach Pfeffer latched onto a through-ball from Raymon Gaddis, but his strike was well saved by Jaime Penedo.

Los Angeles took the lead in the 23rd minute when Gyasi Zardes fired a strike at goal from inside the box, only to see his effort crash off the post, but Baggio Husidic was on hand to turn the ball home.

The Galaxy doubled their advantage when Zardes caused problems for the visitors once again and he guided the ball into the path of Juninho, who found the bottom corner of the net from close range.

In the second half, the home side added a third goal when Robbie Keane picked out the run of Zardes with a pinpoint pass and the forward volleyed the ball past Brian Sylvestre.

Philadelphia got a goal back in the 58th minute when CJ Sapong collected the ball on the edge of the area and turned his man before rifling an effort into the bottom corner.

However, the Galaxy restored their four-goal lead when Omar Gonzalez knocked the ball into the path of Stefan Ishizaki and he maintained his composure to find the net.

Sebastian Lletget scored the fifth goal for the Galaxy to confirm their commanding victory after he was teed up by Zardes and slotted the ball past Sylvestre.

The Union were denied a late second strike when Cristian Maidana let fly from distance, but his strike crashed off the bar and went over as the Galaxy cruised to a comfortable win.