Everyone knew the points would come. And they did. In a Monday night matchup for the ages, the Los Angeles Rams and the Kansas City Chiefs locked horns in what was predicted to be an all-offense slugfest.

Someone forgot to tell the defenses they were supposed to stay out of the way. In a game that featured wild momentum swings and had five touchdowns in the fourth quarter alone, the teams combined for seven forced turnovers and three defensive touchdowns, providing an unlikely source of scoring in the Rams’ eventual 54-51 victory.

[Rams vs. Chiefs: Ken Belson says this scorefest is just the beginning]

The rare late-season matchup between one-loss teams had been called a Super Bowl preview by many (though the New Orleans Saints might object to that characterization), and the oddsmakers took a look at these thrilling offenses and set a record for over-under in an N.F.L. game, 63.5 points.

The teams surpassed that mark with 2 minutes 14 seconds left in the third quarter. They did not slow down from there, producing not only the highest-scoring “Monday Night Football” game ever, but the third-highest combined score ever, as well as the first game in N.F.L. history in which both teams topped 50 points.