Roberto Pereyra scored a 90th minute second for the Zebrette, after the Lazio players believed that the referee had already blown for full time.
With goalkeeper Federico Marchetti laid out on the turf, and several Biancocelesti players walking off the pitch, the Argentine midfielder scored a 40-yard open goal to secure the home side's win.
And after the final whistle had eventually been blown, Lazio's players on the pitch, and a number of their coaching staff, clashed with the officials. Andre Dias was given a red card for his outburst, Marchetti was seen pushing the referee and Lionel Scaloni was booked for misconduct.
The length of the suspensions, if any, will not be known until Bergonzi files his report on the game, which is due later on Monday evening.
Udinese coach Francesco Guidolin was disappointed to see the ugly scenes mar his side's victory.
"I was disappointed not to be able to see my team enjoy the win because of this incident,” the 56-year-old told Gazzetta dello Sport. “Some of the Lazio players asked me to admit that I had heard the whistle, but I didn't.”
Lazio meanwhile, have refused to comment at this time.