Andrew Taylor and Timmy Donovan have been convicted of manslaughter after killing Liverpool policeman PC Neil Doyle on a Christmas night out.
Ex-semi professional footballer Taylor, 29, landed a fatal punch that ruptured the off-duty officer's neck artery in the attack on 19 December 2014. He was was also found guilty of the assault of PC Michael Steventon.
Donovan, 30, who was the subject of a European arrest warrant after he fled to Germany, was also found guilty of manslaughter.
The pair were acquitted of murder but found guilty of the serious assault of PC Robert Marshall. They will be sentenced 11 September.
Three men in total were accused of causing newly-wed PC Doyle's death. As well as Taylor and Donnovan, Christopher Spendlove, 30, was charged with murder but was acquitted of the charge as well as manslaughter.
Detective Superintendent Mike Shaw of Merseyside Police said an alcohol-fuelled night Taylor and Donnovan had "ruined their own lives".
"Neil and his friends, who were all off duty police officers, were enjoying a Christmas night with colleagues on the night of the attack and the three defendants were also enjoying a night out.
"Sadly, what should have been a good night out for both groups in the run up to Christmas turned in to a nightmare and resulted in the death of Neil Doyle and serious injuries to his colleagues.
"Taylor and Donovan, have also ruined their own lives. They were of previously good character and hadn't been involved in criminality prior to that night. In fact, Taylor, had a promising career ahead of him in the sporting world. But their rash actions, following the consumption of large amounts of alcohol, have ruined what could have been a bright future and their families, are also now left to pick up the pieces.
"Sadly, in drink some people seem to lose their common sense and throw caution to the wind. It's difficult to know what drives people on a night out to punch someone else, but all too often we see the consequences of people who strike out at others after having consumed alcohol."