Has an MLB game ever ended 20-1?
Yes. MLB has seen a final score of 20-1 19 times. It first happened on May 25, 1882, when Buffalo Bisons beat Cleveland Blues, and most recently on September 19, 2025, when Kansas City Royals beat Toronto Blue Jays.
That makes 20-1 the 176th most common final score out of 330 that have ever occurred in MLB. One point away, 21-1 has happened 5 times and 20-2 has happened 17 times. At one point the score disappeared for 77 years, between 1924 and 2001.