The home side had dominated the early stages of the Monday Night Football clash at Selhurst Park and led through Adrian Mariappa, but the defining moment came in the 19th minute when Fulham's Swiss midfielder controlled a long ball on his chest at speed and arrowed a seemingly impossible shot into the top corner of Julian Speroni's goal from the corner of the penalty area.
Fulham went on to take the lead with another brilliant goal from Steve Sidwell on the stroke of half-time and goals from Dimitar Berbatov and Philippe Senderos after the break saw them run out 4-1 winners.
But Neville said the match hinged on the perfect technique of Kasami to bring his side back into the game.
"It was absolutely sensational," he said.
"Up to that point all the momentum was with Crystal Palace, but he made a long run and you just have to watch the finish and admire it.
"It's instinctive, he's on full speed and everything is absolutely perfect. It's absolutely sensational because everything has to be absolutely perfect.
"It's the goal of a lifetime for him, but more importantly it got Fulham back in the game in a really important game.
"Crystal Palace were undone by two unbelievable goals and what could Ian Holloway say at half-time? They were undone by two absolutely unbelievable strikes that you can't defend.
"They were doing well in the game and the goals completely changed the swing. Martin Jol must have been thinking 'wow, two players have produced magical moments for me tonight.'"
Despite the victory, Neville says Fulham have plenty of work to do in the coming weeks and months to avoid a relegation scrap.
But he says the moment of magic from Kasami will take some of the pressure off Jol after some poor early-season form.
"It was a big win for them," Neville added.
"Early on in the game it was a bit worrying for them because Crystal Palace were all over them. The momentum and the crowd was up, but then Kasami's goal changed absolutely everything.
"Obviously Sidwell scored the second, but the first goal was the changing point in the game and it takes the pressure off them momentarily.
"I think in the Premier League you can win a game and you get three or four points up, but then the next week two or three teams below you win and all the pressure's back on again.
"I think they will need more than that win tonight, but it's a good start for Fulham and a big moment for them."