Neymar caused quite a stir on social media following the full-time whistle of PSG's 5-0 drubbing of Celtic at Celtic Park.The Brazilian superstar scored the opener in the 19th minute but was embroiled in a heated rivalry with a young Celtic defender.PSG are considered the second most likely team to win the Champions League this season, according to the bookies.Zinedine Zidane's Real Madrid - who became the first club to win the competition in back-to-back seasons - are the favourites and begin their European campaign at home to APOEL on Wednesday night.The arrival of Neymar and Kylian Mbappe has given the French giants renewed hope of securing the most coveted trophy in club football.PSG's display at Celtic Park suggests they could well go the distance this year.

The Neymar handshake controversy

The 5-0 thrashing of Celtic was marred by an incident caught on camera at full-time.

Neymar refused to shake the hand of 18-year-old Anthony Ralston, who had been marking him in the Champions League opener.

The former Barcelona star was criticised on social media for his behaviour after footage of his handshake rejection went viral.

Why Neymar refused the handshake

However, two videos have since emerged explaining why Neymar chose not to shake the hand of the Celtic academy star.

The young Scottish defender was booked in the 53rd minute for a disgusting challenge on Thiago Motta - he didn't even apologise for the tackle.

Another clip emerged in which Ralston was seen laughing hysterically in the face of Neymar after the Brazilian received a yellow card.

Neymar responded by reminding his opponent of the scoreline.

Despite Ralston's unarguably awful behaviour, should Neymar have shaken his hand regardless?

Brendan Rodgers praised the youngster after Celtic's 5-0 defeat, noting that he was up against the finest winger on the planet.

"I thought he [Ralston] was excellent tonight," said the Celtic boss. "He was playing against the best winger in the world and I thought he did very, very well against him."

The return match will take place in the Parc des Princes on November 22nd.