Just ask Greg Rusedski, who allowed his anger to get the better of him during his second round match against Andy Roddick at Wimbledon.

Leading 5-3 in the third set, Rusedski lost his cool when he mistakenly thought a call from the crowd had actually come from a line judge.

He went on to lose the set and the match, and was fined £1,500 for his comments to the umpire.

So what went wrong for Greg? And how can tennis players control their temper - even if they feel angry inside?

Sports psychologist Gloria Budd says the most important thing is to channel your anger, and make it work for you rather than against you.

John McEnroe made the most of his anger

"What I'd say to Greg is: 'let's work on some techniques to control the anger in a way that you get a positive outcome from it'," she says.

"Greg lost control and his focus was on the anger and frustration. Once that happened that was it - game over."

How to stay in control

Of course, it's easy to say these things after the event, but how do you keep yourself calm in the heat of the battle?

Gloria continues: "It's about controlling your anger in order to get the result you want. Disassociate from it - take yourself up above it.

"If you get yourself into a situation where you're feeling angry or frustrated, rise above it - literally take yourself up.

"Pretend you're on the roof of a building looking down at the event.

"Take the anger and the frustration out of it, and then go back into it and get yourself a positive outcome."

If you get yourself into a situation where you're feeling angry or frustrated, rise above it - literally take yourself up Gloria Budd Sports psychologist