Watch: 'You ask for a yellow card, you get one!' Wayne Barnes scolds Ma'a Nonu with firm warning in heated Champions Cup match

Ma'a Nonu is renowned for looking like a wrecking ball on the rugby field but after a short chat with referee Wayne Barnes in last night's Champions Cup encounter, he resembled more a of scolded schoolboy.

Midway through the second half of Toulon's match against Scarlets, tempers were beginning to boil over as the Scarlets defence were penalised multiple times near their try-line.

It led to Barnes blowing his whistle to talk to Scarlets captain Ken Owens but before he could begin the conversation, Nonu interjected with his own opinion.

"That's a yellow ref!"

Barnes immediately dismissed Nonu so he could speak with Owens but warned him he would come back to him shortly.

After issuing a warning to Owens to talk to his team about their discipline, Barnes immediately called in Nonu for a quick telling-off and another warning.

"Let's make it really clear," Barnes started off.

"You come and ask for a yellow card, you'll get one. Understand?"

Nonu quickly agreed before muttering something under his breathe after Barnes walked off.

Scarlets went on to win the tight contest 30-27.