MOSCOW — British singer Robbie Williams had social media aflutter Thursday when he flipped off a global TV audience in the opening ceremony of the World Cup.

The 44-year-old Williams showed the world the finger during his final song "Rock DJ" as he prowled down the sideline of Luzhniki Stadium before the opening tournament match between host Russia and Saudi Arabia.

Williams changed the lyrics before the extending his middle finger to the camera directly in front of him.

The song usually goes: "Pimpin' ain't easy. Most of them fleece me every night." Instead he sang "Pimpin' ain't easy. Most of them fleece me but I'm doing this for free."

He raised his eyebrows and then raised the finger with a wry expression as dancers gyrated behind him.

"Robbie Williams just flipped off the camera on the most watched event in the world," tweeted one observer.

But Williams, wearing a red leopard print suit, seemed in good spirits as he ended the song, saying "Have a great World Cup everybody" as he waved to the crowd.

Robbie was soon trending worldwide.

A former member of Take That, Williams reportedly has sold 75 million albums worldwide.