Simon And Garfunkel's business manager once had to stop the musicians from getting into a serious fight.

Paul Simon and Art Garfunkel came close to fisticuffs in 1993 at one of their comeback concerts - following their split in 1970 - after getting into a heated argument backstage over a critic who had suggested Garfunkel hadn't contributed equally to the rock duo.

Simon's manager Joseph Rascoff claims the pair would have stabbed one another if he hadn't been there to break it up.

Recalling the bust-up in a forthcoming autobiography, 'Paul Simon: The Life', Rascoff reveals: ''They never came to blows but there was shoving, and I had to step between them.

''I genuinely believed that if there had been a knife on the table one of them would have used it.''

Simon, 76 - who recently announced his farewell tour after 50 years in the music business - also recalls his version of events, in which he claims Garfunkel made him look like a ''fool'' by making him believe he'd messed up their 1974 hit 'The Boxer' at the show.

He remembers: ''During one song, I think it was 'The Boxer', I made a mistake over when to come in, and it threw Artie off for a second.

''But it was an accident; it wasn't intentional.

''So later, we're singing 'Feelin' Groovy', and suddenly Art just stops singing at the part that goes 'Life, I love you', and I'm just left there by myself, trying to figure out what to do.

''I assumed it was another mistake - no big deal.

''But then at intermission, Art comes up to me and says, 'You tried to make me look like a fool on 'The Boxer,' and I said, 'No, Artie, it was a mistake. Mistakes happen, just like you forgot to do Life, I love you.

''That's when he looked me in the eye and said, 'I didn't forget. I just wanted you to see what it feels like to be made a fool of'.''

Despite their fallings out - which were hardly documented - the 'Bridge over Troubled Water' hitmakers continued the rest of their international run in 1993, but they wouldn't hit the road again until 2003.

In 2010, the pair were forced to cancel their 2010 summer tour after Garfunkel suffered a vocal-cord injury.

The duo also argued over Simon (5ft2) being shorter than Garfunkel (5ft 10).

The latter says: ''I remember during a photo session Artie said, 'No matter what happens, I'll always be taller than you.' Did that hurt? I guess it hurt enough for me to remember 60 years later.''