Fulham finds scoring form vs. Palace
Palace took an early lead through Adrian Mariappa in the seventh minute, but Kasami brought Fulham level with one of the best goals of the season so far when he controlled a long ball with his chest and volleyed in with his next touch from the right edge of the area.
Sidwell then added another highlight goal just before halftime when a free kick was blocked by the Palace wall and bounced into his path, and he unleashed another volley from outside the area past goalkeeper Julian Speroni.
Dimitar Berbatov headed in the third in the 50th and Philippe Senderos added the fourth with another volley from close range five minutes later.
The win lifts Fulham into 14th place with 10 points from eight games and eases some of the pressure on manager Martin Jol after a poor start to the season. Palace remained second to last, with just three points in its first season back in the top flight.
''It was unbelievably important to get a result,'' Jol said. ''We needed the three points, so now ... that's a better position for Fulham.''
It was only the second time that Fulham scored four goals away in the Premier League, and the first two will be talked about for some time.
Kasami's was the most impressive, as he ran onto a long by Sascha Riether and chested the ball ahead of him as he broke into the area. Before the ball had time to land, he struck a perfect volley - with his weaker right foot - that sailed past the flailing Speroni and into the far corner.
''Yeah, that was an unbelievable goal and I'm very pleased,'' Kasami said. ''I saw I could run in the space, and it came perfect for my chest and I took it direct with my right foot.''
Jol said even he was stunned by Kasami's strike, ''because I haven't seen him do it before'' in training.
''It was a real good goal from a talented boy,'' Jol said. ''It could be one of the goals of the season.''
Sidwell's strike may have earned similar praise, had it not come shortly after Kasami's.
After Bryan Ruiz's free kick slammed into the wall, the ball dropped to the 30-year-old midfielder who thrashed a dipping volley into the top left corner to put the visitors in front.
''I knew as soon as it left my foot it was going in,'' Sidwell said.
Palace never recovered and Fulham dominated after the break. Berbatov first met Ruiz's corner to head inside the far post and Senderos then met another corner with a flying scissor kick at the far post to complete the comeback.