What is the highest number of own-goals scored in a football game for both teams combined, excluding:
Biggest one I have found so far is Catania's 4 own-goals when losing 5-0 to Internazionale (Inter Milan) making combined 4 own-goals (Source). Youtube link.
A deep Internet search didn't point to any match where 4 or more undeliberate own goals were scored in a single game, except Catania's 4 own-goals for Internazionale that was already mentioned in the question.
But the interesting one that I did find is during Nigeria Nation Wide League Division 3 play-offs, 2 scandalous matches ended with insane scores:
According to BBC:
A journalist who saw Bubayaro's defeat against Police Machine, and who asked not to be identified in order to protect his own safety, told BBC Sport: "In the second half, we started witnessing outrageous own goals, free-kicks and terrible goalkeeping.
Telegraph reports that one player alone has scored 3 own goals in the fixed match:
It was embarrassing that in one of the games, a player scored 11 times while in the other, four goals were scored within a minute and a player scored three own-goals in a match.
This player was identified by Gulf News as the captain of Akurba FC:
The NFF [Nigerian Football Federation] named 28 players as goal scorers — and own goal scorers — in the two games, responsible for a scarcely-believable 146 goals.
Akurba captain Anjide Said Timothy was identified by the NFF as one of the organisers of the “scandalous” results. He scored three own goals in Akurba’s huge loss, the NFF said.
According to this article:
By half-time, Plateau United were 7-0 up, while Police Machine were leading by 6 goals to nil. However, things quickly got out of hand, as both teams’ opponents began to put the ball into their own net following the break, with the games eventually ending 79-0 and 67-0 respectively, earning Plateau United promotion.
As a result, players and officials of clubs involved in two Nigerian promotion play-off games have been banned for life. The four clubs have been banned from the game for 10 years. Unfortunately, none of the articles reveal the exact number of own goals, but we can guess that there were a lot.
