Has an NFL game ever ended 10-9?
It has. 10-9 has been a NFL final 37 times in 18,234 games. The first was Kansas City Cowboys beat Brooklyn Lions on November 7, 1926; the latest was Denver Broncos beat New York Jets on September 29, 2024.
That makes 10-9 the 153rd most common final score out of 1,095 that have ever occurred in NFL. One point away, 11-9 has happened never and 10-10 has happened 24 times. At one point the score disappeared for 26 years, between 1946 and 1972.