Javier Aguirre's Japan made light work of the Middle Eastern side, who had to overcome air strikes, travel restrictions and other complications to compete in Australia.
Yasuhito Endo, Shinji Okazaki, Keisuke Honda and Maya Yoshida scored the goals for Japan, who will face much tougher opposition in their other Group D fixtures versus Iraq and Jordan.
Palestine qualified for their maiden Asian Cup appearance via the AFC Challenge Cup - a tournament for "emerging countries" as defined by the Asian Football Confederation (AFC) - and were completely off the pace at Hunter Stadium, where they ended the game with 10 men.
The disparity in quality was encapsulated by Japan's opening goal with Endo collecting a lay-off by Takashi Inui and then producing a rather timid shot that Palestine goalkeeper and captain Ramzi Saleh failed to stop.
Saleh's dive was well short of Endo's 20-yard strike, which rolled wide of his right glove and inside the post.
But for Palestine, simply getting on the pitch was arguably a victory, with regular defender Haitham Dheeb reportedly having been denied an exit visa by Israel to travel to the continental championships.
The reigning champions hit the front in the eighth minute, however, as Endo became Japan's oldest goalscorer at the Asian Cup.
But the nature of Endo's goal only served to underline how sloppy Japan were playing, with strong winds wreaking havoc on their regular lofted diagonal passes.
In a pedestrian first half, Yuto Nagatomo was arguably Japan's best player and it was the Inter full-back who created the second goal in the 25th minute.
Nagatomo's persistence saw him overlap down the left and keep a long pass in play with a cutback, which eventually fell to Shinji Kagawa, whose shot was nodded past Saleh by Okazaki.
Japan made it 3-0 just before half-time after Mus'ab Al Battat pushed Kagawa in the penalty area and Honda made no mistake from the spot.
Just three minutes after the break and Yoshida extended Japan's lead further with a header from Kagawa's cross.
Palestine had Ahmed Harbi sent off in the 73rd minute for a second yellow card and their best chance to score came eight minutes later when Abdallatif Al Bahdari powered a header just wide of the goal from a free-kick.
Despite his team's comfortable win, Aguirre will surely expect more a polished performance against Iraq on Friday.
