Has an NBA game ever ended 131-120?
It has. 131-120 has been a NBA final 21 times in 73,172 games. The first was Philadelphia Warriors beat New York Knicks on February 2, 1958; the latest was Dallas Mavericks beat Portland Trail Blazers on December 16, 2023.
That makes 131-120 the 952nd most common final score out of 3,189 that have ever occurred in NBA. One point away, 132-120 has happened 28 times and 131-121 has happened 22 times. At one point the score disappeared for 27 years, between 1989 and 2016.