Game, set, snatch.

A vile, grown man sparked outrage after he was caught on camera swiping Polish tennis star Kamil Majchrzak’s hat from an eager young fan at the US Open.

The sophomoric scene unfolded Thursday afternoon as Majchrzak greeted fans and signed autographs courtside following his epic five-set victory over No. 9 seed Karen Khachanov, according to footage from the live broadcast. 5

Majchrzak took off his hat and attempted to hand it to a young boy in the stands — when the greedy guy clutching a tennis ball snatched the memento away and shoved it into his wife’s bag.

“What are you doing?” the outraged boy screamed at the shameless cap caper.

The hat hog ignored the devastated child and then thrust a water bottle into the tennis star’s face for another autograph.

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