Cristiano Ronaldo's foul friends - famous moments when sports stars crack

Real Madrid's Cristiano Ronaldo, right, reacts after referee Ricardo de Burgos shows a red card. Photo / AP

Real Madrid's Cristiano Ronaldo has been banned for pushing a ref - but the football superstar is far from alone when it comes to inappropriate contact with match officials. We check out four of the most famous cases.

1) Unforced error
Frustrated teenage Canadian tennis player Denis Shapovalov whacked a ball into the umpire's eye during a Davis Cup match this year. While not intentional, it was out of line and worse still, Frenchman Arnaud Gabas required surgery on the resulting fractured socket.

Shapovalov was defaulted, fined, and suitably remorseful

"I was in complete shock and regret right away," said Shapovalov. "I kind of blacked out for the next 10 minutes maybe. I remember going to the bench, asking if the ref's OK."

2) The mouths of babes
English football referee Paul Alcock's exaggerated backwards tumble stole the limelight, after he was pushed by crazy Sheffield Wednesday character Paolo Di Canio in 1998. Di Canio was responding to his red card, which caused a red mist.

This year, Alcock told The Sun he was grateful to US President Bill Clinton and intern Monica Lewinsky, whose scandalous liaison "took me off the front pages".

"There was no way you would feign something like that on national TV," Alcock said.

"I ended up being the rogue in the whole thing. I had TV crews outside my house when I got home that night with my four-year-old son asking me to get the Queen to send them away."

3) Head games
Balmain character Steve "Blocker" Roach crossed a line when he patted referee Eddie Ward on the head in 1990 after being sin binned. Roach had earned Ward's ire over his favourite hobby of sledging. Roach was suspended and fined.

BREAKING NEWS: Balmain's Steve Roach suspended for 4 weeks for patting ref Eddie Ward on the head. #NRL pic.twitter.com/LmTBbgeNWV

— The Winfield Cup (@winfield_cup) March 15, 2016

4) Dreadful act
Grumpy Windies fast bowler Colin Croft charged Kiwi umpire Fred Goodall in the back at Christchurch in 1980, as the tourist's view of the local umpiring reached boiling point.

Worse still, Croft has tried to protest his innocence.

"If Fred Goodall was in Hollywood, he'd have picked up an Oscar," he told the Cricket Monthly in 2006. "I'm six foot and 230 pounds. If I'd meant to hit him, he wouldn't have got up. It's crap that I barged him deliberately."

Goodall said it "hurt for a while". Croft seemed to escape any official censure.