Mark Munro (31), from Denny, and James Robertson (27), from Pitlochry, pushed 27-year-old Russell Robertson from Falkirk, over bridge railings at Bainsford Bridge, Falkirk, on May 29, last year, causing him to fall into the Forth and Clyde Canal.
Russell’s body was pulled from the canal more than an hour later. He suffered a skull fracture caused by his head hitting a metal stanchion as he fell.
The High Court in Glasgow heard that he would have been unconscious when he went into the water.
The court heard that all three men had been at the Warehouse nightclub in Falkirk and were making their way home after 3am when an incident occurred.
Robertson was approached by Russell and they began fighting and then Munro who had been on the phone became involved.
The two tipped Russell over in the canal and then ran off without a backward glance.
In court, both men blamed each other.
Munro tried to portray himself as a hero who tried to save Russell, but the jury did not believe him.
Robertson admitted being in an initial struggle with Russell, but claimed he was walking away towards Falkirk when Russell went into the water.
Both men were on trial accused of murdering Russell, but were convicted of the reduced charge of culpable homicide.
Nightclub security manager Kevin Gibney told of how he saw Russell disappear off the bridge as he struggled with Munro and Robertson.
Mr Gibney said: “One minute he was there and the next he was gone. The two gentlemen ran across the road.”
Minutes later Mr Gibney picked out Munro and Robertson to police and they were detained and later charged with murder.
Another eye-witness Cameron Binnie (19) said that he and some friends were waiting at a bus stop near the bridge after a night out at the Warehouse nightclub.
He said it was around 3.20am and they were texting friends and taxi firms trying to get a lift home when he saw three men who he thought were ‘larking about’.
Mr Binnie said: “It looked like play fighting. One of the men had another man in a headlock. I thought it was pals just mucking about.”
The lifeguard said he changed his mind when he saw the two men grab the other man’s legs.
He added: “I just saw them lifting his legs.”
Judge Lady Carmichael deferred sentence until August 23 at the High Court in Edinburgh for background reports and detained both accused in custody.
Defence counsel will give their pleas in mitigation then.